colb-20230719

EXHIBIT 99.1


			Second Quarter 2023 Results •Net income of $133 million, or $0.64 per common share •Operating net income of $169 million, or $0.81 per common share1 •Consolidated asset balances of $54 billion at quarter end •Loan balances of $37 billion and deposit balances of $41 billion at quarter end •Estimated CET1 and total capital ratios of 9.1% and 11.1% at quarter end


COLUMBIA BANKING SYSTEM, INC. REPORTS SECOND QUARTER 2023 RESULTS
$0.64	$0.81	$23.16	$15.02
Earnings per diluted common share	Operating earnings per diluted common share 1	Book value per common share	Tangible book value per common share 1


CEO Commentary
"Our teams continued to drive success during the second quarter, which was characterized by further integration progress and relationship-focused business activity,” said Clint Stein, President and CEO. “We successfully completed planned branch consolidations during the quarter, and though merger-related expenses continued to impact our reported results, we remain on track to achieve our guided cost-savings expectations by the end of the third quarter, with additional opportunities already identified. We are not immune to quantitative actions affecting industry deposit balances and contributing to the modest remix of our deposit base. However, our talented associates, service-driven operating model, and expansion in newer markets provide us with the opportunities and resources to retain our favorable placement within the industry.”
–Clint Stein, President and CEO of Columbia Banking System, Inc.


2Q23 HIGHLIGHTS (COMPARED TO 1Q23)

Net Interest Income and NIM			•Net interest income increased by $109 million or 29% on a linked-quarter basis due to the full quarter run rate as a combined organization, which offset the impact of higher funding costs related to deposit and liability mix shift and rising interest rates.
			•Net interest margin was 3.93%, down 15 basis points from the prior quarter. Excluding purchase accounting accretion and amortization, net interest margin was 3.32%, down 41 basis points from the prior quarter due primarily to higher funding costs.

Non-Interest Income and Expense			•Non-interest income decreased by $15 million due primarily to a $24 million linked-quarter unfavorable change related to cumulative non-merger fair value accounting and hedges.
			•Non-interest expense decreased by $14 million as lower merger-related expenses and the realization of cost savings offset the full quarter run rate of the combined organization.

Credit Quality			•Net charge-offs were 0.30% of average loans and leases (annualized) and centered in the FinPac portfolio.
			•Provision expense of $16 million reflects stabilizing credit trends in the FinPac portfolio, changes in the economic forecasts used in credit models, and portfolio mix changes.
			•Non-performing assets to total assets was 0.15%.

Capital			•Estimated total risk-based capital ratio of 11.1% and estimated common equity tier 1 risk-based capital ratio of 9.1%.
			•Declared a quarterly cash dividend of $0.36 per common share on May 15, 2023, which was paid June 15, 2023.

Notable items			•Sold $373 million in non-relationship loans and reclassified an additional $118 million to loans held for sale.
			•Entered into an agreement to sell approximately one-third of the MSR portfolio, which relates to the non-relationship component of the serviced loan portfolio.
			•$30 million in merger-related expenses.


2Q23 KEY FINANCIAL DATA

PERFORMANCE METRICS	2Q23		1Q23		2Q22
Return on average assets	1.00%		(0.14)%		1.04%
Return on average tangible common equity1	16.63%		(2.09)%		12.23%
Operating return on average assets1	1.27%		0.74%		1.06%
Operating return on average tangible common equity1	21.13%		10.64%		12.49%
Net interest margin	3.93%		4.08%		3.41%
Adjusted net interest margin1	3.32%		3.73%		3.40%
Efficiency ratio	62.60%		79.71%		59.12%

INCOME STATEMENT ($ in 000s, excl. per share data)	2Q23		1Q23		2Q22
Net interest income	$483,975		$374,698		$248,170
Provision for credit losses	$16,014		$105,539		$18,692
Non-interest income	$39,678		$54,735		$55,235
Non-interest expense	$328,559		$342,818		$179,574
Pre-provision net revenue 1	$195,094		$86,615		$123,831
Operating pre-provision net revenue1	$243,114		$195,730		$125,994
Earnings per common share - diluted 2	$0.64		($0.09)		$0.61
Operating earnings per common share - diluted 1,2	$0.81		$0.46		$0.62
Dividends paid per share 2	$0.36		$0.35		$0.35

BALANCE SHEET	2Q23		1Q23		2Q22
Total assets	$53.6	B	$54.0	B	$30.1	B
Loans and leases	$37.0	B	$37.1	B	$24.4	B
Total deposits	$40.8	B	$41.6	B	$26.1	B
Book value per common share 2	$23.16		$23.44		$19.47
Tangible book value per share1,2	$15.02		$15.12		$19.42
Tangible book value per share, ex AOCI 1,2	$17.03		$16.56		$21.80

Investor Contact

Jacquelynne "Jacque" Bohlen, SVP/Investor Relations Director, 503-727-4117, [email protected]

1 "Non-GAAP" financial measure. See GAAP to Non-GAAP Reconciliation for the comparable GAAP measurement.

2 Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 2

Organizational Update

Columbia Banking System, Inc. ("Columbia", "we", or "our") completed the planned consolidation of 47 branches during the latter half of the second quarter. We remain on track to realize the previously communicated $135 million in annualized cost-savings expectations by the end of the third quarter.

On February 28, 2023, Columbia completed its merger with Umpqua Holdings Corporation ("UHC"), combining the two premier banks in the Northwest to create one of the largest banks headquartered in the West ("the merger"). Columbia's financial results for any periods ended prior to February 28, 2023 reflect UHC results only on a standalone basis. In addition, Columbia's reported financial results for the first quarter of 2023 reflect UHC financial results only until the closing of the merger after the close of business on February 28, 2023. As a result of these two factors, Columbia's financial results for the first and second quarters of 2023 and the six months ended June 30, 2023 may not be directly comparable to prior reported periods. The number of shares issued and outstanding, earnings per share, additional paid-in capital, and all references to share quantities or metrics of Columbia have been retrospectively restated to reflect the equivalent number of shares issued in the merger as the merger was treated as a reverse merger. Under the reverse acquisition method of accounting, the assets and liabilities of Columbia as of February 28, 2023 ("historical Columbia") were recorded at their respective fair values.

Net Interest Income

Net interest income was $484 million for the second quarter of 2023, up $109 million from the prior quarter. The increase, which includes $74 million of purchase accounting accretion and amortization compared to $32 million in the first quarter, reflects the benefit of a full quarter run rate as a combined organization, partially offset by higher funding costs related to deposit and liability mix shift and rising interest rates.

Columbia's net interest margin was 3.93% for the second quarter of 2023, down 15 basis points from 4.08% for the first quarter of 2023. Excluding purchase accounting accretion and amortization, the net interest margin was 3.32% for the second quarter of 2023 compared to 3.73% for the first quarter of 2023. The cost of interest-bearing deposits increased 32 basis points on a linked-quarter basis to 1.64% for the second quarter of 2023, which compares to 1.83% for both the month of June and at June 30, 2023. Please refer to the Q2 2023 Earnings Presentation for additional net interest margin change details and interest rate sensitivity information as well as our non-GAAP disclosures in this press release for the impact of purchase accounting accretion and amortization on individual line items.

Non-interest Income

Non-interest income was $40 million for the second quarter of 2023, down $15 million from the prior quarter. A $24 million unfavorable change in cumulative fair value adjustments and mortgage servicing rights ("MSR") hedging activity offset the benefit of the full quarter run rate as a combined organization. A net fair value loss of $16 million in the second quarter compares to a net fair value gain of $8 million in the first quarter, as detailed in our non-GAAP disclosures. The planned sale of approximately one-third of our MSR and the associated accounting treatment was the primary driver of the ineffectiveness of our MSR hedging activity during the second quarter. The transaction, which we expect to close at the end of the third quarter or beginning of the fourth quarter, relates to a non-relationship component of our serviced loan portfolio, and the transaction is expected to be accretive to capital given the impact to risk-weighted assets from the reduction in our MSR balance.

Non-interest Expense

Non-interest expense was $329 million for the second quarter of 2023, down $14 million from the prior quarter level. The decrease reflects an $86 million decline in merger-related expenses, which were $30 million in the second quarter, and the realization of cost savings, with the impact partially offset by the full quarter run rate of the combined organization. Please refer to the Q2 2023 Earnings Presentation for additional expense details, including an update on realized merger-related cost-savings through June 30, 2023.

Balance Sheet

Total consolidated assets were $53.6 billion as of June 30, 2023, compared to $54.0 billion as of March 31, 2023. Cash and cash equivalents was $3.4 billion as of June 30, 2023, a decrease of $228 million relative to March 31, 2023. We continued to maintain a higher on-balance sheet level of liquidity during the second quarter. Including secured off-balance sheet lines of credit, total available liquidity was $18.1 billion as of June 30, 2023, representing 34% of total assets, 44% of total deposits, and 134% of uninsured deposits. Please refer to the Q2 2023 Earnings Presentation for additional details related to our liquidity position.

Available for sale securities, which are held on balance sheet at fair value, were $9.0 billion as of June 30, 2023, a decrease of $251 million relative to March 31, 2023, as paydowns and a decline in the fair value of the portfolio were only partially offset by accretion of the discount on historical Columbia securities. Please refer to the Q2 2023 Earnings Presentation for additional details related to our securities portfolio.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

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Gross loans and leases were $37.0 billion as of June 30, 2023, essentially unchanged from March 31, 2023, as net organic growth during the quarter was offset by the sale of $373 million in loans and the corresponding reclassification of $118 million in balances to loans held for sale. "We elected to sell approximately $500 million in loans that were transactional in nature during the quarter," commented Chris Merrywell, President of Umpqua Bank. "Our teams remain focused on generating balanced growth through existing and new customer relationships, which contributed to 5% annualized growth in the second quarter when loan sales and transfers are excluded." Please refer to the Q2 2023 Earnings Presentation for additional details related to our loan portfolio, which include underwriting characteristics, the composition of our commercial portfolios, and disclosure related to our office portfolio.

Total deposits were $40.8 billion as of June 30, 2023, a decrease of $751 million relative to March 31, 2023. "Our deposit balances continued to be affected by market liquidity tightening, the impact of inflation on customer spending, and commercial customers' deployment of cash, which includes tax payments," stated Mr. Merrywell. "Declining balances do not reflect customer attrition, and to date we have not experienced any adverse impact from the planned branch consolidations completed during the quarter given our teams' dedication to limiting any potential disruption to customers from the activity." Please refer to the Q2 2023 Earnings Presentation for additional details related to deposit characteristics and flows.

Credit Quality

The allowance for credit losses was $424 million, or 1.15% of loans and leases, as of June 30, 2023, compared to $436 million, or 1.18% of loans and leases, as of March 31, 2023. The provision for credit losses was $16 million for the second quarter of 2023 and is reflective of stabilizing credit trends in the FinPac portfolio; changes between the February 2023 and May 2023 economic forecasts; and portfolio mix changes, which include the reserve release associated with loan sales completed during the quarter. Please refer to the Q2 2023 Earnings Presentation for additional details related to the allowance for credit losses and other credit trends.

Net charge-offs were 0.30% of average loans and leases (annualized) for the second quarter of 2023, compared to 0.23% for the first quarter of 2023. Net charge-off activity continued to be centered in the FinPac portfolio, which experienced an anticipated increase in charge-offs. Bank charge-off activity remained low at 0.03% of average bank loans. As of June 30, 2023, non-performing assets were $80 million, or 0.15% of total assets, compared to $76 million, or 0.14% as of March 31, 2023.

Capital

As of June 30, 2023, Columbia's book value per common share decreased to $23.16, compared to $23.44 at March 31, 2023. The linked-quarter change in book value primarily reflects a change in accumulated other comprehensive (loss) income ("AOCI") to $(419) million at June 30, 2023, compared to $(300) million at the prior quarter-end. The change in AOCI is due primarily to a reduction in the tax-effected net unrealized loss on available for sale securities to $403 million at June 30, 2023, compared to $295 million at March 31, 2023. Tangible book value per common share3 decreased to $15.02, compared to $15.12 at March 31, 2023.

Columbia's estimated total risk-based capital ratio was 11.1% and its estimated common equity tier 1 risk-based capital ratio was 9.1% as of June 30, 2023, compared to 10.9% and 8.9%, respectively, at March 31, 2023. Columbia remains above current “well-capitalized” regulatory minimums. "Our regulatory capital ratios expanded as anticipated during the second quarter, due in part to the realization of loan and investment securities discount accretion," stated Ron Farnsworth, Chief Financial Officer of Columbia. "We expect meaningful capital build over time to enhance future deployment opportunities." The regulatory capital ratios as of June 30, 2023 are estimates, pending completion and filing of Columbia's regulatory reports.

Earnings Presentation and Conference Call Information

Columbia's Q2 2023 Earnings Presentation provides additional disclosure. A copy will be available on our investor relations page: www.columbiabankingsystem.com.

Columbia will host its second quarter 2023 earnings conference call on July 19, 2023, at 2:30 p.m. PT (5:30 p.m. ET). During the call, Columbia's management will provide an update on recent activities and discuss its second quarter 2023 financial results. Participants may register for the call using the below link to receive dial-in details and their own unique PINs or join the audiocast. It is recommended you join 10 minutes prior to the start time.

Join the audiocast: https://edge.media-server.com/mmc/p/9uf3dn2p

Access the replay through Columbia's investor relations page: www.columbiabankingsystem.com

3 "Non-GAAP" financial measure. See GAAP to Non-GAAP Reconciliation for the comparable GAAP measurement.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 4

About Columbia Banking System, Inc.

Columbia (Nasdaq: COLB) is headquartered in Tacoma, Washington and is the parent company of Umpqua Bank, an award-winning western U.S. regional bank based in Lake Oswego, Oregon. In March of 2023, Columbia and Umpqua combined two of the Pacific Northwest's premier financial institutions under the Umpqua Bank brand to create one of the largest banks headquartered in the West and a top-30 U.S. bank. With over $50 billion of assets, Umpqua Bank combines the resources, sophistication and expertise of a national bank with a commitment to deliver personalized service at scale. The bank operates in Arizona, California, Colorado, Idaho, Nevada, Oregon, Utah, and Washington and supports consumers and businesses through a full suite of services, including retail and commercial banking; Small Business Administration lending; institutional and corporate banking; and equipment leasing. Umpqua Bank customers also have access to comprehensive investment and wealth management expertise as well as healthcare and private banking through Columbia Wealth Management and Columbia Trust Company, a subsidiary of Columbia. Learn more at www.columbiabankingsystem.com.

Forward-Looking Statements

This press release includes forward-looking statements within the meaning of the "Safe-Harbor" provisions of the Private Securities Litigation Reform Act of 1995, which management believes are a benefit to shareholders. These statements are necessarily subject to risk and uncertainty and actual results could differ materially due to various risk factors, including those set forth from time to time in our filings with the Securities and Exchange Commission (the "SEC"). You should not place undue reliance on forward-looking statements and we undertake no obligation to update any such statements. Forward-looking statements can be identified by words such as "anticipates," "intends," "plans," "seeks," "believes," "estimates," "expects," "target," "projects," "outlook," "forecast," "will," "may," "could," "should," "can" and similar references to future periods. In this press release we make forward-looking statements about strategic and growth initiatives and the result of such activity. Risks that could cause results to differ from forward-looking statements we make include, without limitation: current and future economic and market conditions, including the effects of declines in housing and commercial real estate prices, high unemployment rates, continued inflation and any recession or slowdown in economic growth particularly in the western United States; economic forecast variables that are either materially worse or better than end of quarter projections and deterioration in the economy that could result in increased loan and lease losses, especially those risks associated with concentrations in real estate related loans; our ability to effectively manage problem credits; the impact of bank failures or adverse developments at or news developments concerning other banks on general investor sentiment regarding the liquidity stability of banks; changes in interest rates that could significantly reduce net interest income and negatively affect asset yields and valuations and funding sources; changes in the scope and cost of FDIC insurance and other coverage; our ability to successfully implement efficiency and operational excellence initiatives; our ability to successfully develop and market new products and technology; changes in laws or regulations; any failure to realize the anticipated benefits of the UHC merger when expected or at all; the possibility that the integration following the UHC merger may be more expensive than anticipated, including as a result of unexpected factors or events, diversion of management’s attention from ongoing business operations and opportunities; potential adverse reactions or changes to business or employee relationships, including those resulting from the completion of the UHC merger and integration of the companies; the effect of geopolitical instability, including wars, conflicts and terrorist attacks; and natural disasters and other similar unexpected events outside of our control. We also caution that the amount and timing of any future common stock dividends or repurchases will depend on the earnings, cash requirements and financial condition of Columbia, market conditions, capital requirements, applicable law and regulations (including federal securities laws and federal banking regulations), and other factors deemed relevant by Columbia's Board of Directors, and may be subject to regulatory approval or conditions.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

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			TABLE INDEX
						Page
			Consolidated Statements of Operations			6
			Consolidated Balance Sheets			8
			Financial Highlights			9
			Loan & Lease Portfolio Balances and Mix			11
			Deposit Portfolio Balances and Mix			12
			Credit Quality - Non-performing Assets			13
			Credit Quality - Allowance for Credit Losses			14
			Consolidated Average Balance Sheets, Net Interest Income, and Yields/Rates			16
			Residential Mortgage Banking Activity			18

			GAAP to Non-GAAP Reconciliation			20

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 6


Columbia Banking System, Inc.
Consolidated Statements of Operations
(Unaudited)
	Quarter Ended										% Change
($ in thousands, except per share data)	Jun 30, 2023		Mar 31, 2023		Dec 31, 2022		Sep 30, 2022		Jun 30, 2022		Seq. Quarter		Year over Year
Interest income:
Loans and leases	$	552,679	$	413,525	$	322,350	$	278,830	$	234,674	34	%	136	%
Interest and dividends on investments:
Taxable	79,036		39,729		18,108		18,175		17,256		99	%	358	%
Exempt from federal income tax	6,817		3,397		1,288		1,322		1,369		101	%	398	%
Dividends	2,581		719		182		86		84		259	%	nm
Temporary investments and interest bearing deposits	34,616		18,581		10,319		5,115		2,919		86	%	nm
Total interest income	675,729		475,951		352,247		303,528		256,302		42	%	164	%
Interest expense:
Deposits	100,408		63,613		31,174		9,090		4,015		58	%	nm
Securities sold under agreement to repurchase and federal funds purchased	1,071		406		323		545		66		164	%	nm
Borrowings	81,004		28,764		8,023		798		50		182	%	nm
Junior and other subordinated debentures	9,271		8,470		7,248		5,491		4,001		9	%	132	%
Total interest expense	191,754		101,253		46,768		15,924		8,132		89	%	nm
Net interest income	483,975		374,698		305,479		287,604		248,170		29	%	95	%
Provision for credit losses	16,014		105,539		32,948		27,572		18,692		(85)	%	(14)	%
Non-interest income:
Service charges on deposits	16,454		14,312		12,139		12,632		12,011		15	%	37	%
Card-based fees	13,435		11,561		9,017		9,115		10,530		16	%	28	%
Financial services and trust revenue	4,512		1,297		25		27		27		248	%	nm
Residential mortgage banking (loss) revenue, net	(2,342)		7,816		(1,812)		17,341		30,544		(130)	%	(108)	%

(Loss) gain on equity securities, net	(697)		2,416		284		(2,647)		(2,075)		(129)	%	(66)	%
Gain on loan and lease sales, net	442		940		1,531		1,525		1,303		(53)	%	(66)	%
BOLI income	4,063		2,790		2,033		2,023		2,110		46	%	93	%
Other income (loss)	3,811		13,603		11,662		(10,571)		785		(72)	%	385	%
Total non-interest income	39,678		54,735		34,879		29,445		55,235		(28)	%	(28)	%
Non-interest expense:
Salaries and employee benefits	163,398		136,092		107,982		109,164		110,942		20	%	47	%
Occupancy and equipment, net	50,550		41,700		34,021		35,042		34,559		21	%	46	%
Intangible amortization	35,553		12,660		1,019		1,025		1,026		181	%	nm
FDIC assessments	11,579		6,113		3,487		3,007		2,954		89	%	292	%
Merger related expenses	29,649		115,898		11,637		769		2,672		(74)	%	nm

Other expenses	37,830		30,355		36,836		28,957		27,421		25	%	38	%
Total non-interest expense	328,559		342,818		194,982		177,964		179,574		(4)	%	83	%
Income (loss) before provision (benefit) for income taxes	179,080		(18,924)		112,428		111,513		105,139		nm		70	%
Provision (benefit) for income taxes	45,703		(4,886)		29,464		27,473		26,548		nm		72	%
Net income (loss)	$	133,377	$	(14,038)	$	82,964	$	84,040	$	78,591	nm		70	%

Weighted average basic shares outstanding (1)	207,977		156,383		129,321		129,319		129,306		33	%	61	%
Weighted average diluted shares outstanding (1)	208,545		156,383		129,801		129,733		129,673		33	%	61	%
Earnings (loss) per common share – basic (1)	$	0.64	$	(0.09)	$	0.64	$	0.65	$	0.61	nm		5	%
Earnings (loss) per common share – diluted (1)	$	0.64	$	(0.09)	$	0.64	$	0.65	$	0.61	nm		5	%

nm = not meaningful

(1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

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Columbia Banking System, Inc.
Consolidated Statements of Operations
(Unaudited)
	Six Months Ended				% Change
($ in thousands, except per share data)	Jun 30, 2023		Jun 30, 2022		Year over Year
Interest income:
Loans and leases	$	966,204	$	449,078	115	%
Interest and dividends on investments:
Taxable	118,765		35,981		230	%
Exempt from federal income tax	10,214		2,741		273	%
Dividends	3,300		170		nm
Temporary investments and interest bearing deposits	53,197		4,272		nm
Total interest income	1,151,680		492,242		134	%
Interest expense:
Deposits	164,021		7,931		nm
Securities sold under agreement to repurchase and federal funds purchased	1,477		129		nm
Borrowings	109,768		99		nm
Junior and other subordinated debentures	17,741		7,150		148	%
Total interest expense	293,007		15,309		nm
Net interest income	858,673		476,933		80	%
Provision for credit losses	121,553		23,496		417	%
Non-interest income:
Service charges on deposits	30,766		23,594		30	%
Card-based fees	24,996		19,238		30	%
Brokerage revenue	5,809		38		nm
Residential mortgage banking revenue, net	5,474		91,330		(94)	%
Gain on sale of debt securities, net	—		2		(100)	%
Gain (loss) on equity securities, net	1,719		(4,736)		nm
Gain on loan and lease sales, net	1,382		3,640		(62)	%
BOLI income	6,853		4,197		63	%
Other income (loss)	17,414		(2,099)		nm
Total non-interest income	94,413		135,204		(30)	%
Non-interest expense:
Salaries and employee benefits	299,490		224,080		34	%
Occupancy and equipment, net	92,250		69,388		33	%
Intangible amortization	48,213		2,051		nm
FDIC assessments	17,692		7,470		137	%
Merger related expenses	145,547		4,950		nm
Other expenses	68,185		54,065		26	%
Total non-interest expense	671,377		362,004		85	%
Income before provision for income taxes	160,156		226,637		(29)	%
Provision for income taxes	40,817		56,889		(28)	%
Net income	$	119,339	$	169,748	(30)	%

Weighted average basic shares outstanding (1)	182,325		129,233		41	%
Weighted average diluted shares outstanding (1)	182,860		129,685		41	%
Earnings per common share – basic (1)	$	0.65	$	1.31	(50)	%
Earnings per common share – diluted (1)	$	0.65	$	1.31	(50)	%

nm = not meaningful

(1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 8


Columbia Banking System, Inc. Consolidated Balance Sheets
(Unaudited)
																% Change
($ in thousands, except per share data)	Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Assets:
Cash and due from banks	$	538,653		$	555,919		$	327,313		$	321,447		$	315,348		(3)	%	71	%
Interest bearing cash and temporary investments	2,868,563			3,079,266			967,330			1,232,412			687,233			(7)	%	317	%
Investment securities:
Equity and other, at fair value	76,361			76,532			72,959			72,277			75,347			0	%	1	%
Available for sale, at fair value	8,998,428			9,249,600			3,196,166			3,136,391			3,416,707			(3)	%	163	%
Held to maturity, at amortized cost	2,388			2,432			2,476			2,547			2,637			(2)	%	(9)	%
Loans held for sale	183,633			49,338			71,647			148,275			228,889			272	%	(20)	%
Loans and leases	37,049,299			37,091,280			26,155,981			25,507,951			24,432,678			0	%	52	%
Allowance for credit losses on loans and leases	(404,603)			(417,464)			(301,135)			(283,065)			(261,111)			(3)	%	55	%
Net loans and leases	36,644,696			36,673,816			25,854,846			25,224,886			24,171,567			0	%	52	%
Restricted equity securities	258,524			246,525			47,144			40,993			10,867			5	%	nm
Premises and equipment, net	368,698			375,190			176,016			165,305			165,196			(2)	%	123	%
Operating lease right-of-use assets	119,255			127,296			78,598			81,729			87,249			(6)	%	37	%
Goodwill	1,029,234			1,030,142			—			—			—			0	%	nm
Other intangible assets, net	666,762			702,315			4,745			5,764			6,789			(5)	%	nm
Residential mortgage servicing rights, at fair value	172,929			178,800			185,017			196,177			179,558			(3)	%	(4)	%
Bank owned life insurance	643,727			641,922			331,759			329,699			328,764			0	%	96	%
Deferred tax asset, net	362,880			351,229			132,823			128,120			70,134			3	%	417	%
Other assets	657,365			653,904			399,800			385,938			389,409			1	%	69	%
Total assets	$	53,592,096		$	53,994,226		$	31,848,639		$	31,471,960		$	30,135,694		(1)	%	78	%
Liabilities:
Deposits
Non-interest bearing	$	16,019,408		$	17,215,781		$	10,288,849		$	11,246,358		$	11,129,209		(7)	%	44	%
Interest bearing	24,815,509			24,370,566			16,776,763			15,570,749			15,003,214			2	%	65	%
Total deposits	40,834,917			41,586,347			27,065,612			26,817,107			26,132,423			(2)	%	56	%
Securities sold under agreements to repurchase	294,914			271,047			308,769			383,569			527,961			9	%	(44)	%
Borrowings	6,250,000			5,950,000			906,175			756,214			6,252			5	%	nm
Junior subordinated debentures, at fair value	312,872			297,721			323,639			325,744			321,268			5	%	(3)	%
Junior and other subordinated debentures, at amortized cost	108,009			108,066			87,813			87,870			87,927			0	%	23	%
Operating lease liabilities	132,099			140,648			91,694			95,512			101,352			(6)	%	30	%

Other liabilities	831,097			755,674			585,111			588,430			440,235			10	%	89	%
Total liabilities	48,763,908			49,109,503			29,368,813			29,054,446			27,617,418			(1)	%	77	%
Shareholders' equity:

Common stock	5,792,792			5,788,553			3,450,493			3,448,007			3,445,531			0	%	68	%
Accumulated deficit	(545,842)			(603,696)			(543,803)			(580,933)			(619,108)			(10)	%	(12)	%
Accumulated other comprehensive loss	(418,762)			(300,134)			(426,864)			(449,560)			(308,147)			40	%	36	%
Total shareholders' equity	4,828,188			4,884,723			2,479,826			2,417,514			2,518,276			(1)	%	92	%
Total liabilities and shareholders' equity	$	53,592,096		$	53,994,226		$	31,848,639		$	31,471,960		$	30,135,694		(1)	%	78	%

Common shares outstanding at period end (2)	208,514			208,429			129,321			129,320			129,318			0	%	61	%
Book value per common share (2)	$	23.16		$	23.44		$	19.18		$	18.69		$	19.47		(1)	%	19	%
Tangible book value per common share (1),(2)	$	15.02		$	15.12		$	19.14		$	18.65		$	19.42		(1)	%	(23)	%
Tangible equity - common (1),(2)	$	3,132,192		$	3,152,266		$	2,475,081		$	2,411,750		$	2,511,487		(1)	%	25	%
Tangible common equity to tangible assets (1)	6.04		%	6.03		%	7.77		%	7.66		%	8.34		%	0.01		(2.30)
nm = not meaningful

(1) See GAAP to Non-GAAP Reconciliation.

(2) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 9


Columbia Banking System, Inc.
Financial Highlights
(Unaudited)
	Quarter Ended															% Change
	Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Per Common Share Data: (5)
Dividends (5)	$	0.36		$	0.35		$	0.35		$	0.35		$	0.35		3	%	3	%
Book value (5)	$	23.16		$	23.44		$	19.18		$	18.69		$	19.47		(1)	%	19	%
Tangible book value (1),(5)	$	15.02		$	15.12		$	19.14		$	18.65		$	19.42		(1)	%	(23)	%
Tangible book value, ex accumulated other comprehensive income (1),(5)	$	17.03		$	16.56		$	22.44		$	22.13		$	21.80		3	%	(22)	%

Performance Ratios:
Efficiency ratio	62.60		%	79.71		%	57.24		%	56.07		%	59.12		%	(17.11)		3.48
Return on average assets ("ROAA")	1.00		%	(0.14)		%	1.04		%	1.09		%	1.04		%	1.14		(0.04)
Pre-provision net revenue ("PPNR") ROAA (1)	1.46		%	0.89		%	1.82		%	1.80		%	1.64		%	0.57		(0.18)
Return on average common equity	10.84		%	(1.70)		%	13.50		%	12.99		%	12.20		%	12.54		(1.36)
Return on average tangible common equity (1)	16.63		%	(2.09)		%	13.53		%	13.02		%	12.23		%	18.72		4.40

Performance Ratios - Operating: (1)
Operating efficiency ratio (1)	54.85		%	53.46		%	52.01		%	51.72		%	58.27		%	1.39		(3.42)
Operating return on average assets (1)	1.27		%	0.74		%	1.24		%	1.33		%	1.06		%	0.53		0.21
Operating PPNR return on average assets (1)	1.82		%	2.01		%	2.10		%	2.12		%	1.66		%	(0.19)		0.16
Operating return on average common equity (1)	13.77		%	8.66		%	16.14		%	15.86		%	12.46		%	5.11		1.31
Operating return on average tangible common equity (1)	21.13		%	10.64		%	16.18		%	15.90		%	12.49		%	10.49		8.64

Average Balance Sheet Yields, Rates, & Ratios:
Yield on loans and leases	5.95		%	5.55		%	4.92		%	4.41		%	3.94		%	0.40		2.01
Yield on earning assets (2)	5.48		%	5.19		%	4.62		%	4.10		%	3.53		%	0.29		1.95
Cost of interest bearing deposits	1.64		%	1.32		%	0.77		%	0.23		%	0.11		%	0.32		1.53
Cost of interest bearing liabilities	2.45		%	1.82		%	1.05		%	0.39		%	0.20		%	0.63		2.25
Cost of total deposits	0.99		%	0.80		%	0.46		%	0.14		%	0.06		%	0.19		0.93
Cost of total funding (3)	1.61		%	1.16		%	0.65		%	0.23		%	0.12		%	0.45		1.49
Net interest margin (2)	3.93		%	4.08		%	4.01		%	3.88		%	3.41		%	(0.15)		0.52

Average interest bearing cash / Average interest earning assets	5.47		%	4.33		%	3.62		%	3.04		%	5.71		%	1.14		(0.24)
Average loans and leases / Average interest earning assets	75.18		%	80.96		%	85.32		%	84.54		%	80.91		%	(5.78)		(5.73)
Average loans and leases / Average total deposits	90.98		%	93.01		%	95.85		%	93.55		%	89.23		%	(2.03)		1.75
Average non-interest bearing deposits / Average total deposits	40.05		%	39.55		%	40.30		%	42.29		%	42.00		%	0.50		(1.95)
Average total deposits / Average total funding (3)	85.59		%	91.36		%	94.52		%	96.34		%	96.66		%	(5.77)		(11.07)

Select Credit & Capital Ratios:
Non-performing loans and leases to total loans and leases	0.22		%	0.20		%	0.22		%	0.20		%	0.18		%	0.02		0.04
Non-performing assets to total assets	0.15		%	0.14		%	0.18		%	0.16		%	0.15		%	0.01		—
Allowance for credit losses to loans and leases	1.15		%	1.18		%	1.21		%	1.16		%	1.12		%	(0.03)		0.03
Total risk-based capital ratio (4)	11.1		%	10.9		%	13.7		%	13.2		%	13.5		%	0.20		(2.40)
Common equity tier 1 risk-based capital ratio (4)	9.1		%	8.9		%	11.0		%	10.7		%	11.0		%	0.20		(1.90)

(1) See GAAP to Non-GAAP Reconciliation.

(2) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

(3) Total funding = Total deposits + Total borrowings.

(4) Estimated holding company ratios.

(5) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 10


Columbia Banking System, Inc.
Financial Highlights
(Unaudited)
	Six Months Ended						% Change
	Jun 30, 2023			Jun 30, 2022			Year over Year
Per Common Share Data: (4)
Dividends (4)	$	0.71		$	0.70		1.43	%

Performance Ratios:
Efficiency ratio	70.30		%	59.07		%	11.23
Return on average assets (ROAA)	0.52		%	1.12		%	(0.60)
Pre-provision net revenue (PPNR) ROAA (1)	1.22		%	1.66		%	(0.44)
Return on average common equity	5.80		%	12.92		%	(7.12)
Return on average tangible common equity (1)	8.09		%	12.96		%	(4.87)

Performance Ratios - Operating: (1)
Operating efficiency ratio (1)	54.24		%	60.09		%	(5.85)
Operating return on average assets (1)	1.04		%	1.04		%	—
Operating PPNR return on average assets (1)	1.90		%	1.55		%	0.35
Operating return on average common equity (1)	11.72		%	12.01		%	(0.29)
Operating return on average tangible common equity (1)	16.34		%	12.05		%	4.29

Average Balance Sheet Yields, Rates, & Ratios:
Yield on loans and leases	5.77		%	3.86		%	1.91
Yield on earning assets (2)	5.35		%	3.38		%	1.97
Cost of interest bearing deposits	1.50		%	0.10		%	1.40
Cost of interest bearing liabilities	2.19		%	0.19		%	2.00
Cost of total deposits	0.90		%	0.06		%	0.84
Cost of total funding (3)	1.42		%	0.11		%	1.31
Net interest margin (2)	3.99		%	3.28		%	0.71

Average interest bearing cash / Average interest earning assets	4.99		%	7.31		%	(2.32)
Average loans and leases / Average interest earning assets	77.64		%	78.88		%	(1.24)
Average loans and leases / Average total deposits	91.87		%	87.00		%	4.87
Average non-interest bearing deposits / Average total deposits	39.69		%	41.68		%	(1.99)
Average total deposits / Average total funding (3)	88.03		%	96.74		%	(8.71)

(1) See GAAP to Non-GAAP Reconciliation.

(2) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

(3) Total funding = Total deposits + Total borrowings.

(4) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 11


Columbia Banking System, Inc.
Loan & Lease Portfolio Balances and Mix
(Unaudited)
	Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			% Change
($ in thousands)	Amount			Amount			Amount			Amount			Amount			Seq. Quarter		Year over Year
Loans and leases:
Commercial real estate:
Non-owner occupied term, net	$	6,434,673		$	6,353,550		$	3,894,840		$	3,846,426		$	3,798,242		1	%	69	%
Owner occupied term, net	5,254,401			5,156,848			2,567,761			2,549,761			2,497,553			2	%	110	%
Multifamily, net	5,622,875			5,590,587			5,285,791			5,090,661			4,768,273			1	%	18	%
Construction & development, net	1,528,924			1,467,561			1,077,346			1,036,931			1,017,297			4	%	50	%
Residential development, net	388,641			440,667			200,838			205,935			194,909			(12)	%	99	%
Commercial:
Term, net	5,449,787			5,906,774			3,029,547			3,003,424			2,904,861			(8)	%	88	%
Lines of credit & other, net	2,268,790			2,184,762			960,054			914,507			920,604			4	%	146	%
Leases & equipment finance, net	1,740,037			1,746,267			1,706,172			1,669,817			1,576,144			0	%	10	%
Residential:
Mortgage, net	6,272,898			6,187,964			5,647,035			5,470,624			5,168,457			1	%	21	%
Home equity loans & lines, net	1,898,958			1,870,002			1,631,965			1,565,094			1,415,722			2	%	34	%
Consumer & other, net	189,315			186,298			154,632			154,771			170,616			2	%	11	%
Total loans and leases, net of deferred fees and costs	$	37,049,299		$	37,091,280		$	26,155,981		$	25,507,951		$	24,432,678		0	%	52	%




Loans and leases mix:
Commercial real estate:
Non-owner occupied term, net	17		%	16		%	15		%	15		%	15		%
Owner occupied term, net	14		%	14		%	10		%	10		%	10		%
Multifamily, net	15		%	15		%	20		%	20		%	20		%
Construction & development, net	4		%	4		%	4		%	4		%	4		%
Residential development, net	1		%	1		%	1		%	1		%	1		%
Commercial:
Term, net	15		%	16		%	12		%	12		%	12		%
Lines of credit & other, net	6		%	6		%	4		%	4		%	4		%
Leases & equipment finance, net	5		%	5		%	6		%	6		%	6		%
Residential:
Mortgage, net	17		%	17		%	21		%	21		%	21		%
Home equity loans & lines, net	5		%	5		%	6		%	6		%	6		%
Consumer & other, net	1		%	1		%	1		%	1		%	1		%
Total	100		%	100		%	100		%	100		%	100		%

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 12


Columbia Banking System, Inc.
Deposit Portfolio Balances and Mix
(Unaudited)
	Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			% Change
($ in thousands)	Amount			Amount			Amount			Amount			Amount			Seq. Quarter		Year over Year
Deposits:
Demand, non-interest bearing	$	16,019,408		$	17,215,781		$	10,288,849		$	11,246,358		$	11,129,209		(7)	%	44	%
Demand, interest bearing	6,300,082			5,900,462			4,080,469			3,903,746			3,723,650			7	%	69	%
Money market	10,115,908			10,681,422			7,721,011			7,601,506			7,284,641			(5)	%	39	%
Savings	3,171,714			3,469,112			2,265,052			2,455,917			2,446,876			(9)	%	30	%
Time	5,227,805			4,319,570			2,710,231			1,609,580			1,548,047			21	%	238	%
Total	$	40,834,917		$	41,586,347		$	27,065,612		$	26,817,107		$	26,132,423		(2)	%	56	%

Total core deposits (1)	$	37,639,368		$	39,155,298		$	25,616,010		$	26,292,548		$	25,619,500		(4)	%	47	%

Deposit mix:
Demand, non-interest bearing	39		%	41		%	38		%	42		%	43		%
Demand, interest bearing	15		%	14		%	15		%	15		%	14		%
Money market	25		%	26		%	29		%	28		%	28		%
Savings	8		%	9		%	8		%	9		%	9		%
Time	13		%	10		%	10		%	6		%	6		%
Total	100		%	100		%	100		%	100		%	100		%

(1) Core deposits are defined as total deposits less time deposits greater than $250,000 and all brokered deposits.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 13


	Columbia Banking System, Inc.
	Credit Quality – Non-performing Assets
	(Unaudited)
		Quarter Ended															% Change
($ in thousands)		Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Non-performing assets:
Loans and leases on non-accrual status:
	Commercial real estate, net	$	10,994		$	15,612		$	5,011		$	5,403		$	5,514		(30)	%	99	%
	Commercial, net	39,316			42,301			25,691			18,652			12,645			(7)	%	211	%
	Residential, net	—			—			—			—			—			nm		nm
	Consumer & other, net	—			—			—			—			—			nm		nm
	Total loans and leases on non-accrual status	50,310			57,913			30,702			24,055			18,159			(13)	%	177	%
Loans and leases past due 90+ days and accruing (1):
	Commercial real estate, net	184			1			1			1			23			nm		nm
	Commercial, net	7,720			151			7,909			5,143			3,311			nm		133	%
	Residential, net (1)	21,370			17,423			19,894			21,411			22,340			23	%	(4)	%
	Consumer & other, net	399			140			134			152			196			185	%	104	%
	Total loans and leases past due 90+ days and accruing (1)	29,673			17,715			27,938			26,707			25,870			68	%	15	%
Total non-performing loans and leases		79,983			75,628			58,640			50,762			44,029			6	%	82	%
Other real estate owned		278			409			203			—			1,868			(32)	%	(85)	%
Total non-performing assets		$	80,261		$	76,037		$	58,843		$	50,762		$	45,897		6	%	75	%


Loans and leases past due 31-89 days		$	73,376		$	78,641		$	64,893		$	53,538		$	34,659		(7)	%	112	%
Loans and leases past due 31-89 days to total loans and leases		0.20		%	0.21		%	0.25		%	0.21		%	0.14		%	(0.01)		0.06
Non-performing loans and leases to total loans and leases (1)		0.22		%	0.20		%	0.22		%	0.20		%	0.18		%	0.02		0.04
Non-performing assets to total assets (1)		0.15		%	0.14		%	0.18		%	0.16		%	0.15		%	0.01		—
nm = not meaningful

(1) Excludes certain mortgage loans guaranteed by Ginnie Mae, which Columbia has the unilateral right to repurchase but has not done so, totaling $1.6 million, $5.4 million, $6.6 million, $1.0 million, and $356,000 at June 30, 2023, March 31, 2023, December 31, 2022, September 30, 2022, and June 30, 2022, respectively.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 14


	Columbia Banking System, Inc.
	Credit Quality – Allowance for Credit Losses
	(Unaudited)
		Quarter Ended															% Change
($ in thousands)		Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Allowance for credit losses on loans and leases (ACLLL)
Balance, beginning of period		$	417,464		$	301,135		$	283,065		$	261,111		$	248,564		39	%	68	%
Initial ACL recorded for PCD loans acquired during the period		—			26,492			—			—			—			(100)	%	nm
Provision for credit losses on loans and leases (1)		15,216			106,498			30,580			28,542			18,787			(86)	%	(19)	%
Charge-offs
	Commercial real estate, net	(174)			—			(128)			—			(8)			nm		nm
	Commercial, net	(32,036)			(19,248)			(14,721)			(9,459)			(9,035)			66	%	255	%
	Residential, net	(4)			(248)			(53)			(4)			—			(98)	%	nm
	Consumer & other, net	(1,264)			(773)			(906)			(929)			(836)			64	%	51	%
	Total charge-offs	(33,478)			(20,269)			(15,808)			(10,392)			(9,879)			65	%	239	%
Recoveries
	Commercial real estate, net	209			58			163			123			73			260	%	186	%
	Commercial, net	4,511			3,058			2,708			2,842			2,934			48	%	54	%
	Residential, net	63			123			24			249			216			(49)	%	(71)	%
	Consumer & other, net	618			369			403			590			416			67	%	49	%
	Total recoveries	5,401			3,608			3,298			3,804			3,639			50	%	48	%
Net (charge-offs) recoveries
	Commercial real estate, net	35			58			35			123			65			(40)	%	(46)	%
	Commercial, net	(27,525)			(16,190)			(12,013)			(6,617)			(6,101)			70	%	351	%
	Residential, net	59			(125)			(29)			245			216			nm		(73)	%
	Consumer & other, net	(646)			(404)			(503)			(339)			(420)			60	%	54	%
	Total net charge-offs	(28,077)			(16,661)			(12,510)			(6,588)			(6,240)			69	%	350	%
Balance, end of period		$	404,603		$	417,464		$	301,135		$	283,065		$	261,111		(3)	%	55	%
Reserve for unfunded commitments
Balance, beginning of period		$	19,029		$	14,221		$	11,853		$	12,823		$	12,918		34	%	47	%
Initial ACL recorded for unfunded commitments acquired during the period		—			5,767			—			—			—			(100)	%	nm
Provision (recapture) for credit losses on unfunded commitments		798			(959)			2,368			(970)			(95)			nm		nm
Balance, end of period		19,827			19,029			14,221			11,853			12,823			4	%	55	%
Total Allowance for credit losses (ACL)		$	424,430		$	436,493		$	315,356		$	294,918		$	273,934		(3)	%	55	%

Net charge-offs to average loans and leases (annualized)		0.30		%	0.23		%	0.19		%	0.11		%	0.11		%	0.07		0.19
Recoveries to gross charge-offs		16.13		%	17.80		%	20.86		%	36.61		%	36.84		%	(1.67)		(20.71)
ACLLL to loans and leases		1.09		%	1.13		%	1.15		%	1.11		%	1.07		%	(0.04)		0.02
ACL to loans and leases		1.15		%	1.18		%	1.21		%	1.16		%	1.12		%	(0.03)		0.03
nm = not meaningful

(1) For the quarter ended March 31, 2023, the provision for credit losses on loans and leases includes $88.4 million initial provision related to non-PCD loans acquired during the period.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 15


Columbia Banking System, Inc.
Credit Quality – Allowance for Credit Losses
(Unaudited)
		Six Months Ended						% Change
($ in thousands)		Jun 30, 2023			Jun 30, 2022			Year over Year
Allowance for credit losses on loans and leases (ACLLL)
Balance, beginning of period		$	301,135		$	248,412		21	%


Initial ACL recorded for PCD loans acquired during the period		26,492			—			nm
Provision for credit losses on loans and leases (1)		121,714			24,483			397	%
Charge-offs
	Commercial real estate, net	(174)			(8)			nm
	Commercial, net	(51,284)			(16,893)			204	%
	Residential, net	(252)			(167)			51	%
	Consumer & other, net	(2,037)			(1,721)			18	%
	Total charge-offs	(53,747)			(18,789)			186	%
Recoveries
	Commercial real estate, net	267			98			172	%
	Commercial, net	7,569			5,479			38	%
	Residential, net	186			389			(52)	%
	Consumer & other, net	987			1,039			(5)	%
	Total recoveries	9,009			7,005			29	%
Net (charge-offs) recoveries
	Commercial real estate, net	93			90			3	%
	Commercial, net	(43,715)			(11,414)			283	%
	Residential, net	(66)			222			(130)	%
	Consumer & other, net	(1,050)			(682)			54	%
	Total net charge-offs	(44,738)			(11,784)			280	%
Balance, end of period		$	404,603		$	261,111		55	%
Reserve for unfunded commitments
Balance, beginning of period		$	14,221		$	12,767		11	%
Initial ACL recorded for unfunded commitments acquired during the period		5,767			—			nm
(Recapture) provision for credit losses on unfunded commitments		(161)			56			(388)	%
Balance, end of period		19,827			12,823			55	%
Total Allowance for credit losses (ACL)		$	424,430		$	273,934		55	%

Net charge-offs to average loans and leases (annualized)		0.27		%	0.10		%	0.17
Recoveries to gross charge-offs		16.76		%	37.28		%	(20.52)


nm = not meaningful

(1) For the six months ended June 30, 2023, the provision for credit losses on loans and leases includes $88.4 million initial provision related to non-PCD loans acquired during the period.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 16


Columbia Banking System, Inc.
Consolidated Average Balance Sheets, Net Interest Income, and Yields/Rates
(Unaudited)
	Quarter Ended
	June 30, 2023						March 31, 2023						June 30, 2022
($ in thousands)	Average Balance		Interest Income or Expense		Average Yields or Rates		Average Balance		Interest Income or Expense		Average Yields or Rates		Average Balance		Interest Income or Expense		Average Yields or Rates
INTEREST-EARNING ASSETS:
Loans held for sale	$	46,794	$	682	5.83	%	$	54,008	$	799	5.92	%	$	264,320	$	2,742	4.15	%
Loans and leases (1)	37,169,315		551,997		5.95	%	29,998,630		412,726		5.55	%	23,550,796		231,932		3.94	%
Taxable securities	8,656,147		81,617		3.77	%	4,960,966		40,448		3.26	%	3,410,091		17,340		2.03	%
Non-taxable securities (2)	865,278		8,010		3.70	%	437,020		4,068		3.72	%	220,327		1,721		3.13	%
Temporary investments and interest-bearing cash	2,704,984		34,616		5.13	%	1,605,081		18,581		4.69	%	1,663,454		2,919		0.70	%
Total interest-earning assets	49,442,518		$	676,922	5.48	%	37,055,705		$	476,622	5.19	%	29,108,988		$	256,654	3.53	%
Goodwill and other intangible assets	1,718,705						623,042						7,379
Other assets	2,379,351						1,747,228						1,240,536
Total assets	$	53,540,574					$	39,425,975					$	30,356,903
INTEREST-BEARING LIABILITIES:
Interest-bearing demand deposits	$	6,131,117	$	17,277	1.15	%	$	4,759,251	$	9,815	0.84	%	$	3,896,553	$	610	0.06	%
Money market deposits	10,362,495		41,703		1.60	%	8,845,784		32,238		1.48	%	7,366,987		1,717		0.09	%
Savings deposits	3,297,138		877		0.11	%	2,686,388		556		0.08	%	2,426,124		199		0.03	%
Time deposits	4,703,967		40,551		3.46	%	3,205,128		21,004		2.66	%	1,618,394		1,489		0.37	%
Total interest-bearing deposits	24,494,717		100,408		1.64	%	19,496,551		63,613		1.32	%	15,308,058		4,015		0.11	%
Repurchase agreements and federal funds purchased	284,347		1,071		1.51	%	281,032		406		0.59	%	512,641		66		0.05	%
Borrowings	6,187,363		81,004		5.25	%	2,352,715		28,764		4.96	%	6,273		50		3.21	%
Junior and other subordinated debentures	405,989		9,271		9.16	%	417,966		8,470		8.22	%	393,964		4,001		4.07	%
Total interest-bearing liabilities	31,372,416		$	191,754	2.45	%	22,548,264		$	101,253	1.82	%	16,220,936		$	8,132	0.20	%
Non-interest-bearing deposits	16,361,541						12,755,080						11,086,376
Other liabilities	871,378						772,870						464,755
Total liabilities	48,605,335						36,076,214						27,772,067
Common equity	4,935,239						3,349,761						2,584,836
Total liabilities and shareholders' equity	$	53,540,574					$	39,425,975					$	30,356,903
NET INTEREST INCOME			$	485,168					$	375,369					$	248,522
NET INTEREST SPREAD					3.03	%					3.37	%					3.33	%
NET INTEREST INCOME TO EARNING ASSETS OR NET INTEREST MARGIN (1), (2)					3.93	%					4.08	%					3.41	%

(1)Non-accrual loans and leases are included in the average balance.

(2)Tax-exempt income has been adjusted to a tax equivalent basis at a 21% tax rate. The amount of such adjustment was an addition to recorded income of approximately $1.2 million for the three months ended June 30, 2023, as compared to $671,000 for the three months ended March 31, 2023 and $352,000 for the three months ended June 30, 2022.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 17


Columbia Banking System, Inc.
Average Rates and Balances
(Unaudited)
	Six Months Ended
	June 30, 2023						June 30, 2022
($ in thousands)	Average Balance		Interest Income or Expense		Average Yields or Rates		Average Balance		Interest Income or Expense		Average Yields or Rates
INTEREST-EARNING ASSETS:
Loans held for sale	$	50,381	$	1,481	5.88	%	$	275,253	$	5,004	3.64	%
Loans and leases (1)	33,603,781		964,723		5.77	%	23,061,173		444,074		3.86	%
Taxable securities	6,818,764		122,065		3.58	%	3,533,930		36,151		2.05	%
Non-taxable securities (2)	652,332		12,078		3.70	%	227,218		3,447		3.03	%
Temporary investments and interest-bearing cash	2,158,071		53,197		4.97	%	2,138,352		4,272		0.40	%
Total interest-earning assets	43,283,329		$	1,153,544	5.35	%	29,235,926		$	492,948	3.38	%
Goodwill and other intangible assets	1,173,900						7,890
Other assets	2,065,036						1,232,496
Total assets	$	46,522,265					$	30,476,312
INTEREST-BEARING LIABILITIES:
Interest-bearing demand deposits	$	5,448,974	$	27,092	1.00	%	$	3,854,596	$	1,108	0.06	%
Money market deposits	9,657,738		73,941		1.54	%	7,503,142		3,125		0.08	%
Savings deposits	2,993,450		1,433		0.10	%	2,416,096		404		0.03	%
Time deposits	3,958,688		61,555		3.14	%	1,685,763		3,294		0.39	%
Total interest-bearing deposits	22,058,850		164,021		1.50	%	15,459,597		7,931		0.10	%
Repurchase agreements and federal funds purchased	282,699		1,477		1.05	%	499,664		129		0.05	%
Borrowings	4,280,632		109,768		5.17	%	6,293		99		3.18	%
Junior and other subordinated debentures	411,944		17,741		8.68	%	387,510		7,150		3.72	%
Total interest-bearing liabilities	27,034,125		$	293,007	2.19	%	16,353,064		$	15,309	0.19	%
Non-interest-bearing deposits	14,518,864						11,046,925
Other liabilities	822,396						426,917
Total liabilities	42,375,385						27,826,906
Common equity	4,146,880						2,649,406
Total liabilities and shareholders' equity	$	46,522,265					$	30,476,312
NET INTEREST INCOME			$	860,537					$	477,639
NET INTEREST SPREAD					3.16	%					3.19	%
NET INTEREST INCOME TO EARNING ASSETS OR NET INTEREST MARGIN (1), (2)					3.99	%					3.28	%

(1)Non-accrual loans and leases are included in the average balance.

(2)Tax-exempt income has been adjusted to a tax equivalent basis at a 21% tax rate. The amount of such adjustment was an addition to recorded income of approximately $1.9 million for the six months ended June 30, 2023, as compared to $706,000 for the same period in 2022.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 18


Columbia Banking System, Inc.
Residential Mortgage Banking Activity
(Unaudited)
	Quarter Ended															% Change
($ in thousands)	Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Residential mortgage banking revenue:
Origination and sale	$	3,166		$	3,587		$	4,252		$	10,515		$	15,101		(12)	%	(79)	%
Servicing	9,167			9,397			9,184			9,529			9,505			(2)	%	(4)	%
Change in fair value of MSR asset:
Changes due to collection/realization of expected cash flows over time	(4,797)			(4,881)			(4,986)			(4,978)			(4,961)			(2)	%	(3)	%
Changes due to valuation inputs or assumptions	(2,242)			(2,937)			(9,914)			16,403			10,899			(24)	%	(121)	%
MSR hedge (loss) gain	(7,636)			2,650			(348)			(14,128)			—			(388)	%	nm
Total	$	(2,342)		$	7,816		$	(1,812)		$	17,341		$	30,544		(130)	%	(108)	%

Closed loan volume for-sale	$	119,476		$	131,726		$	216,833		$	396,979		$	576,532		(9)	%	(79)	%
Gain on sale margin	2.65		%	2.72		%	1.96		%	2.65		%	2.62		%	(0.07)		0.03

Residential mortgage servicing rights:
Balance, beginning of period	$	178,800		$	185,017		$	196,177		$	179,558		$	165,807		(3)	%	8	%
Additions for new MSR capitalized	1,168			1,601			3,740			5,194			7,813			(27)	%	(85)	%
Change in fair value of MSR asset:
Changes due to collection/realization of expected cash flows over time	(4,797)			(4,881)			(4,986)			(4,978)			(4,961)			(2)	%	(3)	%
Changes due to valuation inputs or assumptions	(2,242)			(2,937)			(9,914)			16,403			10,899			(24)	%	(121)	%
Balance, end of period	$	172,929		$	178,800		$	185,017		$	196,177		$	179,558		(3)	%	(4)	%

Residential mortgage loans serviced for others	$	12,723,932		$	12,914,046		$	13,020,189		$	12,997,911		$	12,932,747		(1)	%	(2)	%
MSR as % of serviced portfolio	1.36		%	1.38		%	1.42		%	1.51		%	1.39		%	(0.02)		(0.03)
nm = not meaningful

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 19


Columbia Banking System, Inc.
Residential Mortgage Banking Activity
(Unaudited)
	Six Months Ended						% Change
($ in thousands)	Jun 30, 2023			Jun 30, 2022			Year over Year
Residential mortgage banking revenue:
Origination and sale	$	6,753		$	31,945		(79)	%
Servicing	18,564			18,645			0	%
Change in fair value of MSR asset:
Changes due to collection/realization of expected cash flows over time	(9,678)			(10,308)			(6)	%
Changes due to valuation inputs or assumptions	(5,179)			51,048			(110)	%
MSR hedge loss	(4,986)			—			nm
Total	$	5,474		$	91,330		(94)	%

Closed loan volume for-sale	$	251,202		$	1,225,654		(80)	%
Gain on sale margin	2.69		%	2.61		%	0.08

Residential mortgage servicing rights:
Balance, beginning of period	$	185,017		$	123,615		50	%
Additions for new MSR capitalized	2,769			15,203			(82)	%
Change in fair value of MSR asset:
Changes due to collection/realization of expected cash flows over time	(9,678)			(10,308)			(6)	%
Changes due to valuation inputs or assumptions	(5,179)			51,048			(110)	%
Balance, end of period	$	172,929		$	179,558		(4)	%
nm = not meaningful

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 20

Non-GAAP Financial Measures

In addition to results presented in accordance with generally accepted accounting principles in the United States of America (GAAP), this press release contains certain non-GAAP financial measures. The company believes presenting certain non-GAAP financial measures provides investors with information useful in understanding our financial performance, our performance trends, and our financial position. We utilize these measures for internal planning and forecasting purposes. We, as well as securities analysts, investors, and other interested parties, also use these measures to compare peer company operating performance. We believe that our presentation and discussion, together with the accompanying reconciliations, provides a complete understanding of factors and trends affecting our business and allows investors to view performance in a manner similar to management. These non-GAAP measures should not be considered a substitution for GAAP basis measures and results, and we strongly encourage investors to review our consolidated financial statements in their entirety and not to rely on any single financial measure. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures having the same or similar names.


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation
(Unaudited)
		Quarter Ended															% Change
($ in thousands, except per share data)		Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Total shareholders' equity	a	$	4,828,188		$	4,884,723		$	2,479,826		$	2,417,514		$	2,518,276		(1)	%	92	%
Less: Goodwill		1,029,234			1,030,142			—			—			—			—	%	nm
Less: Other intangible assets, net		666,762			702,315			4,745			5,764			6,789			(5)	%	nm
Tangible common shareholders' equity	b	$	3,132,192		$	3,152,266		$	2,475,081		$	2,411,750		$	2,511,487		(1)	%	25	%
Less: Accumulated other comprehensive (loss) income (AOCI)		$	(418,762)		(300,134)			(426,864)			(449,560)			(308,147)			40	%	36	%
Tangible common shareholders' equity, ex AOCI	c	$	3,550,954		$	3,452,400		$	2,901,945		$	2,861,310		$	2,819,634		3	%	26	%

Total assets	d	$	53,592,096		$	53,994,226		$	31,848,639		$	31,471,960		$	30,135,694		(1)	%	78	%
Less: Goodwill		1,029,234			1,030,142			—			—			—			0	%	nm
Less: Other intangible assets, net		666,762			702,315			4,745			5,764			6,789			(5)	%	nm
Tangible assets	e	$	51,896,100		$	52,261,769		$	31,843,894		$	31,466,196		$	30,128,905		(1)	%	72	%
Common shares outstanding at period end (1)	f	208,514			208,429			129,321			129,320			129,318			0	%	61	%

Total shareholders' equity to total assets ratio	a / d	9.01		%	9.05		%	7.79		%	7.68		%	8.36		%	(0.04)		0.65
Tangible common equity ratio	b / e	6.04		%	6.03		%	7.77		%	7.66		%	8.34		%	0.01		(2.30)
Tangible common equity ratio, ex AOCI	c / e	6.84		%	6.61		%	9.11		%	9.09		%	9.36		%	0.23		(2.52)
Book value per common share (1)	a / f	$	23.16		$	23.44		$	19.18		$	18.69		$	19.47		(1)	%	19	%
Tangible book value per common share (1)	b / f	$	15.02		$	15.12		$	19.14		$	18.65		$	19.42		(1)	%	(23)	%
Tangible book value per common share, ex AOCI (1)	c / f	$	17.03		$	16.56		$	22.44		$	22.13		$	21.80		3	%	(22)	%
nm = not meaningful

(1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 21


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Quarter Ended										% Change
($ in thousands)		Jun 30, 2023		Mar 31, 2023		Dec 31, 2022		Sep 30, 2022		Jun 30, 2022		Seq. Quarter		Year over Year
Non-Interest Income Adjustments

(Loss) gain on equity securities, net		$	(697)	$	2,416	$	284	$	(2,647)	$	(2,075)	(129)	%	(66)	%
Gain (loss) on swap derivatives		1,288		(3,543)		(2,329)		4,194		7,337		nm		(82)	%
Change in fair value of certain loans held for investment		(6,965)		9,488		4,192		(26,397)		(15,210)		(173)	%	(54)	%
Change in fair value of MSR due to valuation inputs or assumptions		(2,242)		(2,937)		(9,914)		16,403		10,899		(24)	%	(121)	%
MSR hedge (loss) gain		(7,636)		2,650		(348)		(14,128)		—		(388)	%	nm
Total non-interest income adjustments	a	$	(16,252)	$	8,074	$	(8,115)	$	(22,575)	$	951	(301)	%	nm

Non-Interest Expense Adjustments
Merger related expenses		$	29,649	$	115,898	$	11,637	$	769	$	2,672	(74)	%	nm
Exit and disposal costs		2,119		1,291		1,966		1,364		442		64	%	379	%
Total non-interest expense adjustments	b	$	31,768	$	117,189	$	13,603	$	2,133	$	3,114	(73)	%	nm

Net interest income (1)	c	$	485,168	$	375,369	$	305,762	$	287,933	$	248,522	29	%	95	%

Non-interest income (GAAP)	d	$	39,678	$	54,735	$	34,879	$	29,445	$	55,235	(28)	%	(28)	%
Less: Non-interest income adjustments	a	16,252		(8,074)		8,115		22,575		(951)		nm		nm
Operating non-interest income (non-GAAP)	e	$	55,930	$	46,661	$	42,994	$	52,020	$	54,284	20	%	3	%

Revenue (GAAP) (1)	f=c+d	$	524,846	$	430,104	$	340,641	$	317,378	$	303,757	22	%	73	%
Operating revenue (non-GAAP) (1)	g=c+e	$	541,098	$	422,030	$	348,756	$	339,953	$	302,806	28	%	79	%

Non-interest expense (GAAP)	h	$	328,559	$	342,818	$	194,982	$	177,964	$	179,574	(4)	%	83	%
Less: Non-interest expense adjustments	b	(31,768)		(117,189)		(13,603)		(2,133)		(3,114)		(73)	%	nm
Operating non-interest expense (non-GAAP)	i	$	296,791	$	225,629	$	181,379	$	175,831	$	176,460	32	%	68	%

Net income (loss) (GAAP)	j	$	133,377	$	(14,038)	$	82,964	$	84,040	$	78,591	nm		70	%
Provision (benefit) for income taxes		45,703		(4,886)		29,464		27,473		26,548		nm		72	%
Income (loss) before provision for income taxes		179,080		(18,924)		112,428		111,513		105,139		nm		70	%
Provision for credit losses		16,014		105,539		32,948		27,572		18,692		(85)	%	(14)	%
Pre-provision net revenue (PPNR) (non-GAAP)	k	195,094		86,615		145,376		139,085		123,831		125	%	58	%
Less: Non-interest income adjustments	a	16,252		(8,074)		8,115		22,575		(951)		nm		nm
Add: Non-interest expense adjustments	b	31,768		117,189		13,603		2,133		3,114		(73)	%	nm
Operating PPNR (non-GAAP)	l	$	243,114	$	195,730	$	167,094	$	163,793	$	125,994	24	%	93	%

Net income (loss) (GAAP)	j	$	133,377	$	(14,038)	$	82,964	$	84,040	$	78,591	nm		70	%
Less: Non-interest income adjustments	a	16,252		(8,074)		8,115		22,575		(951)		nm		nm
Add: Non-interest expense adjustments	b	31,768		117,189		13,603		2,133		3,114		(73)	%	nm
Tax effect of adjustments		(11,981)		(23,565)		(5,459)		(6,116)		(480)		(49)	%	nm
Operating net income (non-GAAP)	m	$	169,416	$	71,512	$	99,223	$	102,632	$	80,274	137	%	111	%
nm = not meaningful

(1) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 22


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Quarter Ended															% Change
($ in thousands, except per share data)		Jun 30, 2023			Mar 31, 2023			Dec 31, 2022			Sep 30, 2022			Jun 30, 2022			Seq. Quarter		Year over Year
Average assets	n	$	53,540,574		$	39,425,975		$	31,637,490		$	30,668,177		$	30,356,903		36	%	76	%
Less: Average goodwill and other intangible assets, net		1,718,705			623,042			5,298			6,343			7,379			176	%	nm
Average tangible assets	o	$	51,821,869		$	38,802,933		$	31,632,192		$	30,661,834		$	30,349,524		34	%	71	%

Average common shareholders' equity	p	$	4,935,239		$	3,349,761		$	2,438,639		$	2,567,266		$	2,584,836		47	%	91	%
Less: Average goodwill and other intangible assets, net		1,718,705			623,042			5,298			6,343			7,379			176	%	nm
Average tangible common equity	q	$	3,216,534		$	2,726,719		$	2,433,341		$	2,560,923		$	2,577,457		18	%	25	%

Weighted average basic shares outstanding (1)	r	207,977			156,383			129,321			129,319			129,306			33	%	61	%
Weighted average diluted shares outstanding (1)	s	208,545			156,383			129,801			129,733			129,673			33	%	61	%

Select Per-Share & Performance Metrics
Earnings-per-share - basic (1)	j / r	$	0.64		$	(0.09)		$	0.64		$	0.65		$	0.61		(811)	%	5	%
Earnings-per-share - diluted (1)	j / s	$	0.64		$	(0.09)		$	0.64		$	0.65		$	0.61		(811)	%	5	%
Efficiency ratio	h / f	62.60		%	79.71		%	57.24		%	56.07		%	59.12		%	(17.11)		3.48
Return on average assets	j / n	1.00		%	(0.14)		%	1.04		%	1.09		%	1.04		%	1.14		(0.04)
Return on average tangible assets	j / o	1.03		%	(0.15)		%	1.04		%	1.09		%	1.04		%	1.18		(0.01)
PPNR return on average assets	k / n	1.46		%	0.89		%	1.82		%	1.80		%	1.64		%	0.57		(0.18)
Return on average common equity	j / p	10.84		%	(1.70)		%	13.50		%	12.99		%	12.20		%	12.54		(1.36)
Return on average tangible common equity	j / q	16.63		%	(2.09)		%	13.53		%	13.02		%	12.23		%	18.72		4.40

Operating Per-Share & Performance Metrics
Operating earnings-per-share - basic (1)	m / r	$	0.81		$	0.46		$	0.77		$	0.79		$	0.62		76	%	31	%
Operating earnings-per-share - diluted (1)	m / s	$	0.81		$	0.46		$	0.76		$	0.79		$	0.62		76	%	31	%
Operating efficiency ratio	i / g	54.85		%	53.46		%	52.01		%	51.72		%	58.27		%	1.39		(3.42)
Operating return on average assets	m / n	1.27		%	0.74		%	1.24		%	1.33		%	1.06		%	0.53		0.21
Operating return on average tangible assets	m / o	1.31		%	0.75		%	1.24		%	1.33		%	1.06		%	0.56		0.25
Operating PPNR return on average assets	l / n	1.82		%	2.01		%	2.10		%	2.12		%	1.66		%	(0.19)		0.16
Operating return on average common equity	m / p	13.77		%	8.66		%	16.14		%	15.86		%	12.46		%	5.11		1.31
Operating return on average tangible common equity	m / q	21.13		%	10.64		%	16.18		%	15.90		%	12.49		%	10.49		8.64

(1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 23


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Six Months Ended				% Change
($ in thousands)		Jun 30, 2023		Jun 30, 2022		Year over Year
Non-Interest Income Adjustments
Gain on sale of debt securities, net		$	—	$	2	(100)	%
Gain (loss) on equity securities, net		1,719		(4,736)		nm
(Loss) gain on swap derivatives		(2,255)		14,384		(116)	%
Change in fair value of certain loans held for investment		2,523		(36,259)		nm
Change in fair value of MSR due to valuation inputs or assumptions		(5,179)		51,048		nm
MSR hedge loss		(4,986)		—		nm
Total non-interest income adjustments	a	$	(8,178)	$	24,439	(133)	%

Non-Interest Expense Adjustments
Merger related expenses		$	145,547	$	4,950	nm
Exit and disposal costs		3,410		3,475		(2)	%
Total non-interest expense adjustments	b	$	148,957	$	8,425	nm

Net interest income (1)	c	$	860,537	$	477,639	80	%

Non-interest income (GAAP)	d	$	94,413	$	135,204	(30)	%
Less: Non-interest income adjustments	a	8,178		(24,439)		(133)	%
Operating non-interest income (non-GAAP)	e	$	102,591	$	110,765	(7)	%

Revenue (GAAP) (1)	f=c+d	$	954,950	$	612,843	56	%
Operating revenue (non-GAAP) (1)	g=c+e	$	963,128	$	588,404	64	%

Non-interest expense (GAAP)	h	$	671,377	$	362,004	85	%
Less: Non-interest expense adjustments	b	(148,957)		(8,425)		nm
Operating non-interest expense (non-GAAP)	i	$	522,420	$	353,579	48	%

Net income (GAAP)	j	$	119,339	$	169,748	(30)	%
Provision for income taxes		40,817		56,889		(28)	%
Income before provision for income taxes		160,156		226,637		(29)	%
Provision for credit losses		121,553		23,496		417	%
Pre-provision net revenue (PPNR) (non-GAAP)	k	281,709		250,133		13	%
Less: Non-interest income adjustments	a	8,178		(24,439)		(133)	%
Add: Non-interest expense adjustments	b	148,957		8,425		nm
Operating PPNR (non-GAAP)	l	$	438,844	$	234,119	87	%

Net income (GAAP)	j	$	119,339	$	169,748	(30)	%
Less: Non-interest income adjustments	a	8,178		(24,439)		(133)	%
Add: Non-interest expense adjustments	b	148,957		8,425		nm
Tax effect of adjustments		(35,546)		4,096		nm
Operating net income (non-GAAP)	m	$	240,928	$	157,830	53	%
nm = not meaningful

(1) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 24


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Six Months Ended						% Change
($ in thousands)		Jun 30, 2023			Jun 30, 2022			Year over Year
Average assets	n	$	46,522,265		$	30,476,312		53	%
Less: Average goodwill and other intangible assets, net		$	1,173,900		$	7,890		nm
Average tangible assets	o	$	45,348,365		$	30,468,422		49	%

Average common shareholders' equity	p	$	4,146,880		$	2,649,406		57	%
Less: Average goodwill and other intangible assets, net		$	1,173,900		$	7,890		nm
Average tangible common equity	q	$	2,972,980		$	2,641,516		13	%

Weighted average basic shares outstanding (1)	r	182,325			129,233			41	%
Weighted average diluted shares outstanding (1)	s	182,860			129,685			41	%

Select Per-Share & Performance Metrics
Earnings-per-share - basic (1)	j / r	$	0.65		$	1.31		(50)	%
Earnings-per-share - diluted (1)	j / s	$	0.65		$	1.31		(50)	%
Efficiency ratio	h / f	70.30		%	59.07		%	11.23
Return on average assets	j / n	0.52		%	1.12		%	(0.60)
Return on average tangible assets	j / o	0.53		%	1.12		%	(0.59)
PPNR return on average assets	k/n	1.22		%	1.66		%	(0.44)
Return on average common equity	j / p	5.80		%	12.92		%	(7.12)
Return on average tangible common equity	j / q	8.09		%	12.96		%	(4.87)

Operating Per-Share & Performance Metrics
Operating earnings-per-share - basic (1)	m / r	$	1.32		$	1.22		8	%
Operating earnings-per-share - diluted (1)	m / s	$	1.32		$	1.22		8	%
Operating efficiency ratio	i / g	54.24		%	60.09		%	(5.85)
Operating return on average assets	m / n	1.04		%	1.04		%	—
Operating return on average tangible assets	m / o	1.07		%	1.04		%	0.03
Operating PPNR return on average assets	l / n	1.90		%	1.55		%	0.35
Operating return on average common equity	m / p	11.72		%	12.01		%	(0.29)
Operating return on average tangible common equity	m / q	16.34		%	12.05		%	4.29

(1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 25


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Quarter Ended										% Change
($ in thousands)		Jun 30, 2023		Mar 31, 2023		Dec 31, 2022		Sep 30, 2022		Jun 30, 2022		Seq. Quarter		Year over Year
Loans and leases interest income	a	$	551,997	$	412,726	$	320,747	$	276,625	$	231,932	34	%	138	%
Less: Acquired loan accretion - rate related (2), (3)	b	30,548		11,832		387		789		1,069		158	%	nm

Less: Acquired loan accretion - credit related (3)	c	7,100		3,806		—		—		—		87	%	nm

Adjusted loans and leases interest income	d=a-b-c	$	514,349	$	397,088	$	320,360	$	275,836	$	230,863	30	%	123	%

Taxable securities interest income	e	$	81,617	$	40,448	$	18,290	$	18,261	$	17,340	102	%	371	%

Less: Acquired taxable securities accretion - rate related	f	34,801		15,356		—		—		—		127	%	nm
Adjusted Taxable securities interest income	g=e-f	$	46,816	$	25,092	$	18,290	$	18,261	$	17,340	87	%	170	%

Non-taxable securities interest income (1)	h	$	8,010	$	4,068	$	1,571	$	1,651	$	1,721	97	%	365	%

Less: Acquired non-taxable securities accretion - rate related	i	2,274		901		—		—		—		152	%	nm
Adjusted Taxable securities interest income (1)	j=h-i	$	5,736	$	3,167	$	1,571	$	1,651	$	1,721	81	%	233	%

Interest income (1)	k	$	676,922	$	476,622	$	352,530	$	303,857	$	256,654	42	%	164	%
Less: Acquired loan and securities accretion - rate related	l=b+f+i	67,623		28,089		387		789		1,069		141	%	nm
Less: Acquired loan accretion - credit related	c	7,100		3,806		—		—		—		87	%	nm
Adjusted interest income (1)	m=k-l-c	$	602,199	$	444,727	$	352,143	$	303,068	$	255,585	35	%	136	%

Interest-bearing deposits interest expense	n	$	100,408	$	63,613	$	31,174	$	9,090	$	4,015	58	%	nm
Less: Acquired deposit accretion	o	(280)		(93)		—		—		—		201	%	nm
Adjusted interest-bearing deposits interest expense	p=n-o	$	100,688	$	63,706	$	31,174	$	9,090	$	4,015	58	%	nm

Interest expense	q	$	191,754	$	101,253	$	46,768	$	15,924	$	8,132	89	%	nm
Less: Acquired interest-bearing liabilities accretion (2)	r	(337)		(150)		(57)		(57)		(57)		125	%	491	%
Adjusted interest expense	s=q-r	$	192,091	$	101,403	$	46,825	$	15,981	$	8,189	89	%	nm

Net Interest Income (1)	t	$	485,168	$	375,369	$	305,762	$	287,933	$	248,522	29	%	95	%
Less: Acquired loan, securities, and interest-bearing liabilities accretion - rate related	u=l-r	67,286		27,939		330		732		1,012		141	%	nm
Less: Acquired loan accretion - credit related	c	7,100		3,806		—		—		—		87	%	nm
Adjusted net interest income (1)	v=t-u-c	$	410,782	$	343,624	$	305,432	$	287,201	$	247,510	20	%	66	%

Average loans and leases	aa	37,169,315		29,998,630		25,855,556		24,886,203		23,550,796		24	%	58	%
Average taxable securities	ab	8,656,147		4,960,966		3,042,044		3,271,185		3,410,091		74	%	154	%
Average non-taxable securities	ac	865,278		437,020		200,825		212,847		220,327		98	%	293	%
Average interest-earning assets	ad	49,442,518		37,055,705		30,305,129		29,437,103		29,108,988		33	%	70	%
Average interest-bearing deposits	ae	24,494,717		19,496,551		16,103,984		15,350,390		15,308,058		26	%	60	%
Average interest-bearing liabilities	af	31,372,416		22,548,264		17,668,730		16,359,575		16,220,936		39	%	93	%

(1)Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

(2)Includes discount accretion related to UHC's 2014 acquisition of Sterling Financial Corporation.

(3)The cumulative fair value discount on historical Columbia loans was established as of February 28, 2023, and the allocation between the credit-related discount and the rate-related discount was established at that time. Our disclosure of credit-related and rate-related discount accretion is an estimate based on the relative allocation of these two items to the discount at closing.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 26


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Quarter Ended										% Change
($ in thousands)		Jun 30, 2023		Mar 31, 2023		Dec 31, 2022		Sep 30, 2022		Jun 30, 2022		Seq. Quarter	Year over Year
Average yield on loans and leases	a / aa	5.95	%	5.55	%	4.92	%	4.41	%	3.94	%	0.40	2.01

Less: Acquired loan accretion - rate related (2),(3)	b / aa	0.33	%	0.16	%	0.01	%	0.01	%	0.02	%	0.17	0.31

Less: Acquired loan accretion - credit related (3)	c / aa	0.08	%	0.05	%	—	%	—	%	—	%	0.03	0.08
Adjusted average yield on loans and leases	d / aa	5.54	%	5.34	%	4.91	%	4.40	%	3.92	%	0.20	1.62

Average yield on taxable securities	e / ab	3.77	%	3.26	%	2.40	%	2.23	%	2.03	%	0.51	1.74

Less: Acquired taxable securities accretion - rate related	f / ab	1.61	%	1.26	%	—	%	—	%	—	%	0.35	1.61
Adjusted average yield on taxable securities	g / ab	2.16	%	2.00	%	2.40	%	2.23	%	2.03	%	0.16	0.13

Average yield on non-taxable securities (1)	h / ac	3.70	%	3.72	%	3.13	%	3.10	%	3.13	%	(0.02)	0.57

Less: Acquired non-taxable securities accretion - rate related	i / ac	1.05	%	0.84	%	—	%	—	%	—	%	0.21	1.05
Adjusted yield on non-taxable securities (1)	j / ac	2.65	%	2.88	%	3.13	%	3.10	%	3.13	%	(0.23)	(0.48)

Average yield on interest-earning assets (1)	k / ad	5.48	%	5.19	%	4.62	%	4.10	%	3.53	%	0.29	1.95
Less: Acquired loan and securities accretion - rate related	l / ad	0.55	%	0.31	%	0.01	%	0.01	%	0.01	%	0.24	0.54
Less: Acquired loan accretion - credit related	c / ad	0.06	%	0.04	%	—	%	—	%	—	%	0.02	0.06
Adjusted average yield on interest-earning assets (1)	m / ad	4.87	%	4.84	%	4.61	%	4.09	%	3.52	%	0.03	1.35

Average rate on interest-bearing deposits	n / ae	1.64	%	1.32	%	0.77	%	0.23	%	0.11	%	0.32	1.53
Less: Acquired deposit accretion	o / ae	—	%	—	%	—	%	—	%	—	%	—	—
Adjusted average rate on interest-bearing deposits	p / ae	1.64	%	1.32	%	0.77	%	0.23	%	0.11	%	0.32	1.53

Average rate on interest-bearing liabilities	q / af	2.45	%	1.82	%	1.05	%	0.39	%	0.20	%	0.63	2.25
Less: Acquired interest-bearing liabilities accretion (2)	r / af	—	%	—	%	—	%	—	%	—	%	—	—
Adjusted average rate on interest-bearing liabilities	s / af	2.45	%	1.82	%	1.05	%	0.39	%	0.20	%	0.63	2.25

Net interest margin (1)	t / ad	3.93	%	4.08	%	4.01	%	3.88	%	3.41	%	(0.15)	0.52
Less: Acquired loan, securities, and interest-bearing liabilities accretion - rate related	u / ad	0.55	%	0.31	%	—	%	0.01	%	0.01	%	0.24	0.54
Less: Acquired loan accretion - credit related	c / ad	0.06	%	0.04	%	—	%	—	%	—	%	0.02	0.06
Adjusted net interest margin (1)	v / ad	3.32	%	3.73	%	4.01	%	3.87	%	3.40	%	(0.41)	(0.08)

(1)Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

(2) Includes discount accretion related to UHC's 2014 acquisition of Sterling Financial Corporation.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 27


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Six Months Ended
($ in thousands)		Jun 30, 2023		Jun 30, 2022		Year over Year
Loans and leases interest income	a	$	964,723	$	444,074	117	%
Less: Acquired loan accretion - rate related (2), (3)	b	42,380		2,501		nm

Less: Acquired loan accretion - credit related (3)	c	10,906		—		nm

Adjusted loans and leases interest income	d=a-b-c	$	911,437	$	441,573	106	%

Taxable securities interest income	e	$	122,065	$	36,151	238	%

Less: Acquired taxable securities accretion - rate related	f	50,157		—		nm
Adjusted Taxable securities interest income	g=e-f	$	71,908	$	36,151	99	%

Non-taxable securities interest income (1)	h	$	12,078	$	3,447	250	%

Less: Acquired non-taxable securities accretion - rate related	i	3,175		—		nm
Adjusted Taxable securities interest income (1)	j=h-i	$	8,903	$	3,447	158	%

Interest income (1)	k	$	1,153,544	$	492,948	134	%
Less: Acquired loan and securities accretion - rate related	l=b+f+i	95,712		2,501		nm
Less: Acquired loan accretion - credit related	c	10,906		—		nm
Adjusted interest income (1)	m=k-l-c	$	1,046,926	$	490,447	113	%

Interest-bearing deposits interest expense	n	$	164,021	$	7,931	nm
Less: Acquired deposit accretion	o	(373)		—		nm
Adjusted interest-bearing deposits interest expense	p=n-o	$	164,394	$	7,931	nm

Interest expense	q	$	293,007	$	15,309	nm
Less: Acquired interest-bearing liabilities accretion (2)	r	(487)		(114)		327	%
Adjusted interest expense	s=q-r	$	293,494	$	15,423	nm

Net Interest Income (1)	t	$	860,537	$	477,639	80	%
Less: Acquired loan, securities, and interest-bearing liabilities accretion - rate related	u=l-r	95,225		2,387		nm
Less: Acquired loan accretion - credit related	c	10,906		—		nm
Adjusted net interest income (1)	v=t-u-c	$	754,406	$	475,252	59	%

Average loans and leases	aa	33,603,781		23,061,173		46	%
Average taxable securities	ab	6,818,764		3,533,930		93	%
Average non-taxable securities	ac	652,332		227,218		187	%
Average interest-earning assets	ad	43,283,329		29,235,926		48	%
Average interest-bearing deposits	ae	22,058,850		15,459,597		43	%
Average interest-bearing liabilities	af	27,034,125		16,353,064		65	%

(1)Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

(2)Includes discount accretion related to UHC's 2014 acquisition of Sterling Financial Corporation.

Columbia Banking System, Inc. Reports Second Quarter 2023 Results

July 19, 2023

Page 28


Columbia Banking System, Inc.
GAAP to Non-GAAP Reconciliation - Continued
(Unaudited)
		Six Months Ended
($ in thousands)		Jun 30, 2023		Jun 30, 2022		Year over Year
Average yield on loans and leases	a / aa	5.77	%	3.86	%	1.91

Less: Acquired loan accretion - rate related (2),(3)	b / aa	0.25	%	0.02	%	0.23

Less: Acquired loan accretion - credit related (3)	c / aa	0.07	%	—	%	0.07
Adjusted average yield on loans and leases	d / aa	5.45	%	3.84	%	1.61

Average yield on taxable securities	e / ab	3.58	%	2.05	%	1.53

Less: Acquired taxable securities accretion - rate related	f / ab	1.48	%	—	%	1.48
Adjusted average yield on taxable securities	g / ab	2.10	%	2.05	%	0.05

Average yield on non-taxable securities (1)	h / ac	3.70	%	3.03	%	0.67

Less: Acquired non-taxable securities accretion - rate related	i / ac	0.98	%	—	%	0.98
Adjusted yield on non-taxable securities (1)	j / ac	2.72	%	3.03	%	(0.31)

Average yield on interest-earning assets (1)	k / ad	5.35	%	3.38	%	1.97
Less: Acquired loan and securities accretion - rate related	l / ad	0.45	%	0.02	%	0.43
Less: Acquired loan accretion - credit related	c / ad	0.05	%	—	%	0.05
Adjusted average yield on interest-earning assets (1)	m / ad	4.85	%	3.36	%	1.49

Average rate on interest-bearing deposits	n / ae	1.50	%	0.10	%	1.40
Less: Acquired deposit accretion	o / ae	—	%	—	%	—
Adjusted average rate on interest-bearing deposits	p / ae	1.50	%	0.10	%	1.40

Average rate on interest-bearing liabilities	q / af	2.19	%	0.19	%	2.00
Less: Acquired interest-bearing liabilities accretion (2)	r / af	—	%	—	%	—
Adjusted average rate on interest-bearing liabilities	s / af	2.19	%	0.19	%	2.00

Net interest margin (1)	t / ad	3.99	%	3.28	%	0.71
Less: Acquired loan, securities, and interest-bearing liabilities accretion - rate related	u / ad	0.44	%	0.02	%	0.42
Less: Acquired loan accretion - credit related	c / ad	0.05	%	—	%	0.05
Adjusted net interest margin (1)	v / ad	3.50	%	3.26	%	0.24

(1)Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate.

(2) Includes discount accretion related to UHC's 2014 acquisition of Sterling Financial Corporation.

2nd Quarter 2023 Earnings Presentation July 19, 2023

Disclaimer FORWARD-LOOKING STATEMENTS This presentation includes forward-looking statements within the meaning of the "Safe-Harbor" provisions of the Private Securities Litigation Reform Act of 1995, which management believes are a benefit to shareholders. These statements are necessarily subject to risk and uncertainty and actual results could differ materially due to various risk factors, including those set forth from time to time in our filings with the Securities and Exchange Commission (the "SEC"). You should not place undue reliance on forward-looking statements and we undertake no obligation to update any such statements. Forward-looking statements can be identified by words such as "anticipates," "intends," "plans," "seeks," "believes," "estimates," "expects," "target," "projects," "outlook," "forecast," "will," "may," "could," "should," "can" and similar references to future periods. In this presentation we make forward-looking statements about strategic and growth initiatives and the result of such activity. Risks that could cause results to differ from forward-looking statements we make include, without limitation: current and future economic and market conditions, including the effects of declines in housing and commercial real estate prices, high unemployment rates, continued inflation and any recession or slowdown in economic growth particularly in the western United States; economic forecast variables that are either materially worse or better than end of quarter projections and deterioration in the economy that could result in increased loan and lease losses, especially those risks associated with concentrations in real estate related loans; our ability to effectively manage problem credits; the impact of bank failures or adverse developments at or news developments concerning other banks on general investor sentiment regarding the liquidity stability of banks; changes in interest rates that could significantly reduce net interest income and negatively affect asset yields and valuations and funding sources; changes in the scope and cost of FDIC insurance and other coverage; our ability to successfully implement efficiency and operational excellence initiatives; our ability to successfully develop and market new products and technology; changes in laws or regulations; any failure to realize the anticipated benefits of the UHC merger when expected or at all; the possibility that the integration following the UHC merger may be more expensive than anticipated, including as a result of unexpected factors or events, diversion of management’s attention from ongoing business operations and opportunities; potential adverse reactions or changes to business or employee relationships, including those resulting from the completion of the UHC merger and integration of the companies; the effect of geopolitical instability, including wars, conflicts and terrorist attacks; and natural disasters and other similar unexpected events outside of our control. We also caution that the amount and timing of any future common stock dividends or repurchases will depend on the earnings, cash requirements and financial condition of Columbia, market conditions, capital requirements, applicable law and regulations (including federal securities laws and federal banking regulations), and other factors deemed relevant by Columbia's Board of Directors, and may be subject to regulatory approval or conditions. NON-GAAP FINANCIAL MEASURES In addition to results in accordance with GAAP, this presentation contains certain non-GAAP financial measures. A reconciliation of GAAP to non-GAAP measures is included in the Appendix. We believe presenting certain non-GAAP financial measures provides investors with information useful in understanding our financial performance, our performance trends, and our financial position. We utilize these measures for internal planning and forecasting purposes. We, as well as securities analysts, investors, and other interested parties, also use these measures to compare peer company operating performance. We believe that our presentation and discussion, together with the accompanying reconciliations, provide a complete understanding of factors and trends affecting our business and allows investors to view performance in a manner similar to management. These non-GAAP measures should not be considered a substitution for GAAP basis measures and results, and we strongly encourage investors to review our consolidated financial statements in their entirety and not to rely on any single financial measure. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures having the same or similar names. REVERSE ACQUISITION METHOD OF ACCOUNTING On February 28, 2023, Columbia Banking System, Inc. ("Columbia", "we" or "our") completed its merger (“the merger”) with Umpqua Holdings Corporation ("UHC"). Columbia's financial results for any periods ended prior to February 28, 2023 reflect UHC results only on a standalone basis unless explicitly stated otherwise. In addition, Columbia's reported financial results for the first quarter of 2023 reflect UHC financial results only until the closing of the merger after the close of business on February 28, 2023. As a result of these two factors, Columbia's financial results for the first and second quarters of 2023 and the six months ended June 30, 2023 may not be directly comparable to prior reported periods. The number of shares issued and outstanding, earnings per share, additional paid-in capital, and all references to share quantities or metrics of Columbia have been retrospectively restated to reflect the equivalent number of shares issued in the merger as the merger was treated as a reverse merger. Under the reverse acquisition method of accounting, the assets and liabilities of Columbia as of February 28, 2023 ("historical Columbia") were recorded at their respective fair values. 2

STRATEGIC UPDATES AND FORWARD OUTLOOK

Merger Update: Cost Synergies Remain on Track for Completion by September 30, 2023 4 Annualized Cost Synergies Realized by Period End Q4 2022 Q1 2023 Q2 2023 Q3 2023 $— $50 $100 $150 $30 million(1) $59 million(1) $105 million(1) $135+ million(1) ■ We expect to achieve $135 million in annualized cost synergies by September 30, 2023(1), and we have already identified additional opportunities above our target. ■ Cost synergies realized ahead of the February 28, 2023 merger close were primarily driven by departing associates that were not slated to be part of the go-forward organization, though there were some real estate and contract-related savings achieved as well in anticipation of closing. ■ The core systems conversion was completed March 20, 2023, but it is not reflected in the run rate until Q2 2023(1) due to the timing of related synergies. ■ The consolidation of 47 branches was completed in the latter half of Q2 2023. FTE, 42% Branch Consolidations, 20% Other Real Estate, 9% Services & Contracts, 28% Other, 1% Expected Composition of Cost Synergies at September 30, 2023 (1) Realized synergies are annualized and reflect what is achieved or expected to be achieved at the end of the quarter; the full amount is not included in the full-quarter run rate.

Merger Update: Purchase Accounting Accretion and Amortization Provides a Meaningful Net Benefit to Income and Capital (1) Table does not capture all assets and liabilities with an associated fair value discount or premium. Assets and liabilities not presented have a significantly smaller impact on income through the accretion or amortization of their discount or premium. (2) See slide 8 for near-term interest income and non-interest expense expectations related to the items outlined in this table. (3) The cumulative fair value discount on historical Columbia loans was established as of February 28, 2023, and the allocation between the credit-related discount and the rate-related discount was established at that time. Our disclosure of credit-related and rate-related discount accretion is an estimate based on the relative allocation of these two items to the discount at closing. Adjustment at Closing Remaining Balances at Select Purchase Accounting Items (1) February 28, 2023 March 31, 2023 June 30, 2023 (2) Notes ITEMS TO ACCRETE THROUGH INTEREST INCOME: Available for sale securities - rate discount $(1,011) million $(629) million $(609) million While an adjustment to historical Columbia securities’ book value was $1.0 billion at closing, the purchase discount that will accrete into interest income over time was $0.6 billion when previously existing purchase premiums and the discount associated with bonds sold as part of the Q1 2023 portfolio restructuring were eliminated. Loans - rate discount (3) $(618) million $(600) million $(558) million Purchase accounting related to loans sold and reclassified to held for sale during Q2 2023 caused a larger reduction in the purchase discount than what was booked through interest income during the quarter. Total rate discount on loans and securities $(1,629) million $(1,229) million $(1,167) million Loans - credit mark (3) $(130) million $(107) million $(94) million Purchase accounting related to loans sold and reclassified to held for sale during Q2 2023 caused a larger reduction in the purchase discount than what was booked through interest income during the quarter. Total discount on loans and securities $(1,759) million $(1,336) million $(1,261) million Fair value discounts are accreted into interest income using the effective interest method, which amortizes the discount over the life of the loan or security. ITEM TO AMORTIZE THROUGH NON-INTEREST EXPENSE: Core deposit intangible $710 million $698 million $664 million CDI amortizes through non-interest expense over 10 years using the sum-of-the-years-digits method. 5

Liquidity Overview Select Balance Sheet Items: Combined Basis Pre-Closing and Consolidated Basis Post-Closing (1) Three Months Ended Sequential Quarter Change ($ in millions) Jun 30, 2023 Mar 31, 2023 Dec 31, 2022 Q2 2023 Required divestitures - associated deposits $— $— $547 $— Brokered deposits 2,346 1,630 867 716 Public deposits 2,425 2,556 2,758 (131) Customer accounts 36,064 37,400 39,569 (1,336) Total Deposits $40,835 $41,586 $43,741 ($751) Repurchase agreements $295 $271 $404 $24 Term debt $6,250 $5,950 $1,860 $300 Cash and cash equivalents $3,407 $3,635 $1,589 ($228) Securities(2) $9,001 $9,252 $9,832 ($251) Loans $37,049 $37,091 $37,759 ($42) Total Available Liquidity at June 30, 2023 ($ in millions) Total off-balance sheet liquidity (available lines of credit): $10,342 Cash and equivalents, less reserve requirement 3,100 Excess bond collateral 4,683 Total available liquidity $18,125 TOTAL AVAILABLE LIQUIDITY AS A PERCENTAGE OF: Assets of $53.6 billion at June 30, 2023 34 % Deposits of $40.8 billion at June 30, 2023 44 % Uninsured deposits of $13.5 billion at June 30, 2023 134 % Total Off-Balance Sheet Liquidity Available at June 30, 2023 ($ in millions) Gross Availability Utilization Net Availability FHLB lines $12,120 $6,220 $5,900 Federal Reserve Discount Window 1,592 — 1,592 Federal Reserve Term Funding Program 2,250 — 2,250 Uncommitted lines of credit 600 — 600 Total off-balance sheet liquidity $16,562 $6,220 $10,342 6 ■ We continue to maintain an elevated cash position on the balance sheet to maintain flexibility, and we intend to continue to do so for the foreseeable future. ■ Market liquidity tightening, the impact of inflation on customer spending, and businesses’ use of cash continued to pressure customer deposit balances during the second quarter. ■ Uninsured deposits were $13.5 billion at June 30, 2023, representing 33% of total deposits. Available liquidity of $18.1 billion was 134% of uninsured deposits at that time. (1) All data presented in the above table combine historical Columbia data and historical UHC data for the three months ended December 31, 2022 (before the merger’s February 28, 2023 close) to provide a consistent comparison of the changes that occurred when viewing the combined organization. (2) Available-for-sale and held-to-maturity securities. Held to maturity securities were only 0.03% of the portfolio at June 30, 2023 and relate to local community housing bonds.

Available for Sale Securities Portfolio at June 30, 2023 ($ in millions) Current Par Amortized Cost Unrealized Gains Unrealized Losses Fair Value % of Total AFS Portfolio Effective Duration Book Yield U.S. Treasuries $422 $406 $— ($10) $397 4 % 2.6 3.32 % U.S. Agencies 1,162 1,179 2 (89) 1,093 12 % 4.7 2.79 % Mortgage-backed securities - residential agency 3,346 3,120 2 (266) 2,856 32 % 7.2 3.20 % Collateralized mortgage obligations (1) 1,462 1,366 — (122) 1,244 14 % 6.1 3.38 % Obligations of states and political subdivisions 1,145 1,082 7 (26) 1,064 12 % 5.0 3.37 % Commercial mortgage-backed securities - agency 2,568 2,387 1 (43) 2,345 26 % 5.0 4.71 % Total available for sale securities $10,105 $9,540 $12 ($556) $8,999 5.7 3.58 % Percentage of Current Par 94 % — % (6) % 89 % 7 Available for Sale Securities Portfolio Percentage Gain / Loss at June 30, 2023 Unrealized Gain, 25% Unrealized Loss, 75% $2.2 billion ▪ net unrealized gain position ▪ 4.30% yield at 6/30 $6.8 billion ▪ net unrealized loss position ▪ 3.36% yield at 6/30 Securities Portfolio Overview (1) Portfolio includes $276 million in high-quality non-agency collateralized mortgage obligations (“CMO”) that were in a small unrealized loss position at June 30, 2023 (amortized cost of $279 million). The remaining $1.0 billion of the portfolio is comprised of residential agency CMOs. ■ The percentage of the available for sale (“AFS”) securities in an unrealized gain position declined to 25% of the portfolio at June 30, 2023, from 66% at March 31, 2023, due to higher interest rates. However, of the securities that changed from an unrealized gain position to an unrealized loss position, the average change in value was only $296 thousand. ■ The total AFS securities portfolio had a book yield of 3.58% and an effective duration of 5.7 at June 30, 2023, essentially unchanged from March 31, 2023. ■ Outside of equity securities, all securities were classified as AFS and carried on the balance sheet at fair value at June 30, 2023, with exception of $2.4 million in local community housing bonds classified as held to maturity; there is no unrealized loss associated with this portfolio, which was 0.03% of total securities.

Outlook (1) Six months ended June 30, 2023 and Full-Year 2023 impacted by the February 28, 2023 merger close. (2) Non-GAAP basis. See slide 16 for reconciliation. (3) Non-GAAP basis; see reconciliation in this table and on slide 13. Excludes non-operating and merger-related items. Results (1) Full-Year 2023 Outlook (1) Three Months Ended Six Months Ended June 30, 2023 June 30, 2023 As of April 26, 2023 As of July 19, 2023 Notes Average earning assets $49b $43b $45b - $46b $45b - $46b Assumes cash balance at 3/31 remains consistent through remainder of 2023 Net interest margin (“NIM”) - adjusted (2) 3.32% 3.50% 3.55% - 3.65% 3.20% - 3.40% Forward outlook does not include any additional changes to the fed funds rate through 2023; incorporates a Q3 2023 adjusted NIM in the 3.1% - 3.3% range, with the lower end assuming funding remix trends similar to Q2 2023 and the upper end assuming the funding mix stabilizes Net interest margin - GAAP 3.93% 3.99% 4.15% - 4.25% 3.75% - 3.95% In addition to the items affecting the adjusted NIM, the GAAP NIM will be affected by the timing of payoff or paydown of loans and securities with an associated discount relative to our outlook Purchase accounting accretion - loans $38mm $53mm $135mm - $145mm $120mm - $130mm Slower prepayment activity reduced our near-term outlook for PAA realization; an increase in payoff or paydown speeds would increase income, and a decrease in speeds would decrease income compared to our outlook Purchase accounting accretion - securities $37mm $53mm $145mm - $155mm $115mm - $125mm Non-interest expense - excluding CDI and merger-related costs (3) $263mm $478mm $965mm - $980mm ~$1 billion Estimated FDIC special assessment (anticipated in Q3 2023) is the driver of the increase in our expense outlook between periods; we continue to anticipate a Q4 run rate of $240mm - $250mm (not annualized) excluding CDI amortization and merger-related costs CDI amortization $36mm $48mm ~$116mm ~$116mm Not included in adjusted non-interest expense detailed above Merger-related costs $30mm $146mm ~$160mm ~$160mm Not included in adjusted non-interest expense detailed above 8

FINANCIAL HIGHLIGHTS AND SUMMARY FINANCIAL STATEMENTS Q2 2023

Performance Ratios Footnotes: (1) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate. (2) Non-GAAP financial measure. A reconciliation to the comparable GAAP measurement is provided on slide 16. (3) Non-GAAP financial measure. A reconciliation to the comparable GAAP measurement is provided at the end of this slide presentation. For the Quarter Ended Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Reported Net interest margin (1) 3.93 % 4.08 % 4.01 % 3.88 % 3.41 % Efficiency ratio (1) 62.60 % 79.71 % 57.24 % 56.07 % 59.12 % Return on average assets 1.00 % (0.14) % 1.04 % 1.09 % 1.04 % Pre-provision net revenue (PPNR) return on average assets (1), (3) 1.46 % 0.89 % 1.82 % 1.80 % 1.64 % Return on average common equity 10.84 % (1.70) % 13.50 % 12.99 % 12.20 % Return on average tangible common equity (3) 16.63 % (2.09) % 13.53 % 13.02 % 12.23 % Operating and Adjusted Adjusted net interest margin (1), (2) 3.32 % 3.73 % 4.01 % 3.87 % 3.40 % Operating efficiency ratio (1), (3) 54.85 % 53.46 % 52.01 % 51.72 % 58.27 % Operating return on average assets (3) 1.27 % 0.74 % 1.24 % 1.33 % 1.06 % Operating PPNR return on average assets (1), (3) 1.82 % 2.01 % 2.10 % 2.12 % 1.66 % Operating return on average common equity (3) 13.77 % 8.66 % 16.14 % 15.86 % 12.46 % Operating return on average tangible common equity (3) 21.13 % 10.64 % 16.18 % 15.90 % 12.49 % Q2 2023 Highlights (compared to Q1 2023) ■ Operating results include the initial provision in Q1 2023 related to non-PCD loans added through the merger, and reported results further include merger- related expenses. These items meaningfully impact performance ratios where applicable. ■ Net interest margin decreased 15 basis points to 3.93%. Excluding purchase accounting accretion and amortization, net interest margin decreased 41 basis points to 3.32% due to higher funding costs and the full-quarter impact of holding a larger cash position on balance sheet to retain flexibility. ■ Profitability ratios improved as merger- related impacts lessened and the realization of cost synergies continued. We remain on track to achieve the guided $135 million in synergies by the end of Q3 2023. 10

Selected Period-End Balance Sheet Footnotes: Tables may not foot due to rounding. “AOCI” = Accumulated other comprehensive income. (1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958. (2) Non-GAAP financial measure. A reconciliation to the comparable GAAP measurement is provided in the appendix of this slide presentation. ($ in millions, except per-share data) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 ASSETS: Total assets $53,592.1 $53,994.2 $31,848.6 $31,472.0 $30,135.7 Interest bearing cash and temporary investments 2,868.6 3,079.3 967.3 1,232.4 687.2 Investment securities available for sale, fair value 8,998.4 9,249.6 3,196.2 3,136.4 3,416.7 Loans and leases, gross 37,049.3 37,091.3 26,156.0 25,508.0 24,432.7 Allowance for credit losses on loans and leases (404.6) (417.5) (301.1) (283.1) (261.1) Goodwill and other intangibles, net 1,696.0 1,732.5 4.7 5.8 6.8 LIABILITIES AND EQUITY: Deposits 40,834.9 41,586.3 27,065.6 26,817.1 26,132.4 Securities sold under agreements to repurchase 294.9 271.0 308.8 383.6 528.0 Borrowings 6,250.0 5,950.0 906.2 756.2 6.3 Total shareholders' equity 4,828.2 4,884.7 2,479.8 2,417.5 2,518.3 RATIOS AND PER-SHARE METRICS: Loan to deposit ratio 90.7% 89.2% 96.6% 95.1% 93.5% Book value per common share (1) $23.16 $23.44 $19.18 $18.69 $19.47 Tangible book value per common share (1), (2) $15.02 $15.12 $19.14 $18.65 $19.42 Tangible book value per common share, excluding AOCI (1), (2) $17.03 $16.56 $22.44 $22.13 $21.80 Tangible common equity to tangible assets (2) 6.0% 6.0% 7.8% 7.7% 8.3% Tangible common equity to tangible assets, excluding AOCI (2) 6.8% 6.6% 9.1% 9.1% 9.4% 11 Q2 2023 Highlights (compared to Q1 2023) ■ Q1 2023 results were impacted by the closing of the merger on February 28, 2023 and the addition of historical Columbia balances at fair value. ■ Net organic loan growth in Q2 2023 was offset by the sale of $373 million in loans and the corresponding reclassification of $118 million in balances to held for sale; loans and leases expanded at a 5% annualized growth rate excluding the impact. ■ Deposits contracted as balances continued to be affected by market liquidity tightening, the impact of inflation on customer spending, and commercial customers’ deployment of cash. A mix of brokered deposits and FHLB advances supplemented the decline in customer balances, as detailed on slide 6.

Summary Income Statement Footnotes: Tables may not foot due to rounding. (1) Periods prior to February 28, 2023, have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958. (2) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate. (3) Non-GAAP financial measure. A reconciliation to the comparable GAAP measurement is provided at the end of this slide presentation. For the Quarter Ended ($ in millions, except per-share data) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Net interest income before provision $484.0 $374.7 $305.5 $287.6 $248.2 Provision for credit losses 16.0 105.5 32.9 27.6 18.7 Net interest income after provision 468.0 269.2 272.5 260.0 229.5 Non-interest income 39.7 54.7 34.9 29.4 55.2 Non-interest expense 328.6 342.8 195.0 178.0 179.6 Income (loss) before provision (benefit) for income taxes 179.1 (18.9) 112.4 111.5 105.1 Provision (benefit) for income taxes 45.7 (4.9) 29.5 27.5 26.5 Net income (loss) $133.4 ($14.0) $83.0 $84.0 $78.6 Earnings (loss) per share, diluted (1) $0.64 ($0.09) $0.64 $0.65 $0.61 Non-interest expense, excluding merger-related expenses (3) $299.0 $226.9 $183.3 $177.2 $176.9 Pre-provision net revenue (2), (3) $195.1 $86.6 $145.4 $139.1 $123.8 Operating pre-provision net revenue (2), (3) $243.1 $195.7 $167.1 $163.8 $126.0 Operating net income (3) $169.4 $71.5 $99.2 $102.6 $80.3 Operating earnings per share, diluted (1), (3) $0.81 $0.46 $0.76 $0.79 $0.62 12 Q2 2023 Highlights (compared to Q1 2023) ■ Q1 2023 results include only one month of the combined company’s operations. ■ Net interest income includes $74 million of purchase accounting accretion and amortization (PAA), compared to $32 million in Q1 2023. ■ Non-interest income decreased by $15 million as a result of a $24 million unfavorable change in cumulative fair value adjustments and mortgage servicing rights hedging activity. ■ Non-interest expense, which includes $30 million in merger-related expenses, decreased by $14 million as lower merger- related expenses and the realization of cost savings offset the full quarter run rate of the combined organization. ■ Provision expense in Q1 2023 includes an initial provision of $88 million for historical Columbia non-PCD loans.

Income Statement Component Details For the Quarter Ended June 30, 2023 LESS: EQUALS LESS: EQUALS ($ in thousands, except per-share data) GAAP Income Non-Operating Items (1) Operating Income (2) Merger-Related Items (3) Adjusted Operating Income (2) Interest income $675,729 $— $675,729 $74,723 $601,006 Interest expense 191,754 — 191,754 (337) 192,091 Net interest income 483,975 — 483,975 74,386 409,589 Provision for credit losses 16,014 — 16,014 — 16,014 Net interest income after provision 467,961 — 467,961 74,386 393,575 Non-interest income 39,678 (16,252) 55,930 — 55,930 Non-interest expense 328,559 31,768 296,791 35,553 261,238 Income before provision for income taxes 179,080 (48,020) 227,100 38,833 188,267 Provision for income taxes 45,703 (11,981) 57,684 9,708 47,976 Net income $133,377 ($36,039) $169,416 $29,125 $140,291 Revenue $523,653 ($16,252) $539,905 $74,386 $465,519 Pre-provision net revenue (2) $195,094 ($48,020) $243,114 $38,833 $204,281 Net interest margin (4) 3.93 % NA 3.93 % 0.61 % 3.32 % Efficiency ratio (4) 62.60 % 7.75 % 54.85 % (1.12) % 55.97 % PPNR return on assets (2), (4) 1.46 % (0.36) % 1.82 % 0.29 % 1.53 % Return on assets 1.00 % (0.27) % 1.27 % 0.22 % 1.05 % Return on equity 10.84 % (2.93) % 13.77 % 2.37 % 11.40 % Return on tangible common equity (2) 16.63 % (4.50) % 21.13 % 3.64 % 17.49 % Earnings per share, diluted $0.64 ($0.17) $0.81 $0.14 $0.67 13 Q2 2023 Highlights ■ GAAP results were adversely impacted by 17 cents of non-operating items that include cumulative fair value adjustments, hedging activity, and merger-related expenses. PAA and CDI amortization provided a net benefit of 14 cents to EPS. ■ Excluding non-operating and merger- related items, adjusted operating EPS was $0.67, return on assets was 1.05%, and return on tangible common equity was 17.5%. ■ We expect the net impact of merger- related items (PAA and CDI amortization) to continue to add to EPS and build capital in future quarters. ■ See appendix for data for the quarter ended March 31, 2023.Footnotes: All dollar values exclude tax equivalent adjustments; all ratios, where relevant, include this adjustment. (1) Non-operating income and expense items are detailed at the end of this slide presentation. Non-operating expense includes $30 million of merger-related expenses. (2) All items in this column represent non-GAAP financial measures and should be reviewed alongside the GAAP reconciliation in this table. PPNR, PPNR return on assets, and return on tangible common equity are also non-GAAP measures for all ratios presented, including those in the GAAP column; a reconciliation is provided at the end of this presentation. (3) Merger-related items include purchase accounting accretion and amortization (PAA) captured in interest income and interest expense and CDI amortization of $36 million. (4) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate and is included in the calculation of this ratio.

INCOME STATEMENT HIGHLIGHTS Q2 2023

($ in millions) Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 Net Interest Income $248.2 $287.6 $305.5 $374.7 $484.0 Acquired loan, securities, and interest-bearing liabilities accretion - rate related (1),(2) (1.0) (0.7) (0.3) (27.9) (67.3) Acquired loan accretion - credit related (2) — — — (3.8) (7.1) Net Interest Income excluding purchase accounting adjustments (“PAA”) (3) $247.2 $286.9 $305.2 $343.0 $409.6 Net Interest Income ($ in m ill io ns ) Net Interest Income $248.2 $287.6 $305.5 $374.7 $484.0 Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 $200.0 $250.0 $300.0 $350.0 $400.0 $450.0 $500.0 ($ in m ill io ns ) Net Interest Income excluding Purchase Accounting Adjustments ("PAA") ³ $247.2 $286.9 $305.2 $343.0 $409.6 Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 $200.0 $250.0 $300.0 $350.0 $400.0 $450.0 15 Note: All dollar values exclude tax equivalent adjustments. (1) Includes discount accretion related to UHC's 2014 acquisition of Sterling Financial Corporation. (2) The cumulative fair value discount on historical Columbia loans was established as of February 28, 2023, and the allocation between the credit-related discount and the rate-related discount was established at that time. Our disclosure of credit-related and rate-related discount accretion is an estimate based on the relative allocation of these two items to the discount at closing. (3) All items in this row represent non-GAAP financial measures and should be reviewed alongside the GAAP reconciliation in this table.

Net Interest Margin Footnotes: (1) Chart Abbreviations: “LHFI” = loans held for investment. (2) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate. (3) Includes discount accretion related to UHC's 2014 acquisition of Sterling Financial Corporation. (4) The cumulative fair value discount on historical Columbia loans was established as of February 28, 2023, and the allocation between the credit-related discount and the rate-related discount was established at that time. Our disclosure of credit-related and rate-related discount accretion is an estimate based on the relative allocation of these two items to the discount at closing. (5) All items in this row represent non-GAAP financial measures and should be reviewed alongside the GAAP reconciliation in this table. Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 Net Interest Margin (2) 3.41 % 3.88 % 4.01 % 4.08 % 3.93 % Acquired loan, securities, and interest-bearing liabilities accretion - rate related (3), (4) (0.01) % (0.01) % — % (0.31) % (0.55) % Acquired loan accretion - credit related (4) — % — % — % (0.04) % (0.06) % Net Interest Margin excluding PAA (2), (5) 3.40 % 3.87 % 4.01 % 3.73 % 3.32 % Net Interest Margin Comparison 3.41% 3.88% 4.01% 4.08% 3.93% 3.40% 3.87% 4.01% 3.73% 3.32% Net Interest Margin Net Interest Margin excluding PAA Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 —% 1.00% 2.00% 3.00% 4.00% 5.00% Net Interest Margin: Q1 2023 vs Q2 2023 4.08% 0.38% 0.30% 0.05% 0.06% (0.38)% (0.54)% (0.02)% 3.93% Q1 2023 Reported LHFI-ex PAA¹ LHFI- PAA¹ Invest- ments Interest- Bearing Cash Deposits Term Debt Other Inputs Q2 2023 Reported 16

Loan Repricing Detail (1), (2) ($ in millions) Q1 2023 Q2 2023 Q1 2023 Q2 2023 Fixed $ 16,205 $ 15,806 43 % 42 % Prime 3,168 2,897 8 % 8 % 1 Month 6,773 7,451 18 % 20 % Floating 9,941 10,348 26 % 28 % Prime 406 430 1 % 1 % 1 Month — 274 — % 1 % 6 Month 6,398 5,883 17 % 16 % 1 Year 1,274 1,293 3 % 3 % 3 Year 277 425 1 % 1 % 5 Year 2,286 2,269 6 % 6 % 10 Year 911 937 3 % 2 % Adjustable 11,552 11,511 31 % 30 % Total $ 37,698 $ 37,665 100 % 100 % Loan Maturities at June 30, 2023 <=6 7 to 12 13 to 24 25 to 36 37 to 60 61+ ($ in millions) Months Months Months Months Months Months Total Fixed $ 1,810 $ 181 $ 573 $ 846 $ 2,210 $ 10,186 $ 15,806 Floating 1,479 1,032 975 703 1,372 4,787 10,348 Adjustable 201 132 272 346 704 9,856 11,511 Total $ 3,490 $ 1,345 $ 1,820 $ 1,895 $ 4,286 $ 24,829 $ 37,665 Interest Rate Sensitivity: Loans Floors: Floating and Adjustable Rate Loans at June 30, 2023 (3) ($ in millions) No Floor At Floor (4) Above Floor Total Floating $6,216 $20 $4,112 $10,348 Adjustable 2,005 1,291 8,215 11,511 Total $8,221 $1,311 $12,327 $21,859 % of Total 38% 6% 56% 100% 17 Footnotes: (1) Index rates are mapped to the closest material index. (2) Loan totals on this slide do not include purchase accounting adjustments. Deferred fees and costs also drive variances between loan totals on this slide and loan totals in the earnings press release. (3) Loans were grouped into three buckets: (1) No Floor: no contractual floor on the loan; (2) At Floor: current rate = floor; (3) Above Floor: current rate exceeds floor. The amount above the floor was based on the current margin plus the current index assuming the loan repriced on June 30, 2023. The adjustable loans may not reprice until well into the future, depending on the timing and size of interest rate changes. (4) At June 30, 2023, $1.3 billion in loans representing 6% of the loan portfolio were at a floor. Of these loan balances, $1.2 billion require an upward rate movement of 25 basis basis points or less to move off their floor.

Interest Rate Sensitivity: Balance Sheet Interest Rate Simulation Impact on Net Interest Income (1), (2) June 30, 2023 March 31, 2023 December 31, 2022 Ramp Shock Ramp Shock Ramp Shock Year 1 Year 2 Year 1 Year 2 Year 1 Year 2 Year 1 Year 2 Year 1 Year 2 Year 1 Year 2 Up 200 basis points (0.8)% (0.7)% (1.3)% 0.6% (0.4)% 0.3% (0.1)% 1.7% 1.1% 4.2% 2.7% 5.6% Up 100 basis points (0.4)% (0.3)% (0.7)% 0.3% (0.2)% 0.2% —% 0.9% 0.6% 2.2% 1.4% 2.9% Down 100 basis points (0.8)% (2.1)% (1.0)% (1.8)% (1.0)% (2.7)% (2.3)% (3.4)% (2.4)% (6.0)% (4.9)% (6.9)% Down 200 basis points (1.5)% (4.3)% (3.1)% (5.0)% (2.0)% (5.7)% (4.9)% (7.3)% (5.1)% (12.9)% (10.6)% (14.8)% Down 300 basis points (2.4)% (6.9)% (5.6)% (8.6)% (3.3)% (9.5)% (8.1)% (12.0)% (7.8)% (19.7)% (16.3)% (22.6)% Footnotes: (1) For the scenarios shown, the interest rate simulations assume a parallel and sustained shift in market interest rates ratably over a twelve-month period (ramp) or immediately (shock). There is no change in the composition of the size of the balance sheet in either scenario. Interest rate sensitivity in the first year of the net interest income simulation for increasing interest rate ramp scenarios is negatively impacted by the cost of non-maturity deposits repricing immediately while interest earning assets reprice at a slower rate. (2) The simulation repricing beta applied to interest-bearing deposits in the rising rate scenarios is 53% for all periods presented. Betas applied are for future repricing assuming future rate changes, and the simulations assume an immediate repricing impact. ■ We continue to manage the balance sheet to protect its sensitivity to a declining interest rate environment. ■ The potential adverse impact to net interest income in a declining interest rate environment was significantly lower at June 30, 2023, compared to December 31, 2022. For example, under the down 300 basis points ramp scenario, our June 30, 2023 simulation anticipates a 2.4% decline in net interest income for year 1 compared to a 7.8% decline for the same scenario under our December 31, 2022 simulation. ■ The cost of interest-bearing deposits was 1.83% for both the month of June and at June 30, 2023. 18 Deposit and Funding Repricing Betas During the Current Rising-Rate Cycle** Effective Fed Funds Rate (Daily Avg.) Cost of Combined Company** Interest- Bearing Deposits Total Deposits Total Funding Q2 2023 4.99% 1.64% 0.99% 1.61% Q1 2023 4.52% 1.32% 0.80% 1.16% Q4 2022 3.65% 0.62% 0.35% 0.51% Q3 2022 2.20% 0.22% 0.12% 0.18% Q2 2022 0.76% 0.11% 0.06% 0.10% Q1 2022 0.12% 0.09% 0.05% 0.08% Q4 2021 0.08% 0.10% 0.05% 0.09% Variance: Peak (Peak Value less Q4 2021) +4.91% +1.54% +0.94% +1.52% Beta - Cycle-to-Date 31% 19% 31% **Note: Interest rate simulations present data on a legal company basis: Data displayed at June 30, 2023 and March 31, 2023 represent the combined company and data displayed at December 31, 2022 represents historical UHC data only. Deposit and funding repricing beta data present combined company results as if historical Columbia and historical UHC were one company for all periods through December 31, 2022; the quarters ended March 31, 2023 and June 30, 2023 are presented on a legal basis given the merger. The beta presentation is calculated in this manner for comparison purposes.

Non-Interest Income Footnotes: Tables may not foot due to rounding. (1) Commercial product revenue includes Swaps, Syndication, and International Banking revenue. For the quarter ended ($ in millions) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Service charges on deposits $16.5 $14.3 $12.1 $12.6 $12.0 Card-based fees 13.4 11.6 9.0 9.1 10.5 Financial services and trust revenue 4.5 1.3 — — — Residential mortgage banking revenue, net (2.3) 7.8 (1.8) 17.3 30.5 Gain (loss) on equity securities, net (0.7) 2.4 0.3 (2.6) (2.1) Gain on loan and lease sales, net 0.4 0.9 1.5 1.5 1.3 BOLI income 4.1 2.8 2.0 2.0 2.1 Other Income Commercial product revenue (1) $3.0 $1.4 $5.3 $6.4 $4.1 Commercial servicing revenue 0.4 0.9 0.9 0.7 0.7 Loan-related fees 3.3 3.4 3.2 3.2 3.1 Change in fair value of certain loans held for investment (7.0) 9.5 4.2 (26.4) (15.2) Misc. Income 2.8 1.9 0.4 1.3 0.8 Swap Derivative Gain/(Loss) 1.3 (3.5) (2.3) 4.2 7.3 19 Q2 2023 Highlights (compared to Q1 2023) ■ Q1 2023 results include only one month of the combined company’s operations. ■ Financial services and trust revenue benefited from the earnings stream added through Columbia Wealth Management. ■ Mortgage banking revenue was adversely impacted by the ineffectiveness of mortgage servicing rights (“MSR”) hedges during the quarter due to the planned sale of approximately one-third of the MSR portfolio and the associated accounting treatment. ■ Higher swap revenue and a favorable change in the valuation of the swap derivative positively impacted non- interest income by $6.6 million compared to Q1 2023.

BALANCE SHEET HIGHLIGHTS Q2 2023

Q2 2023 Loan Roll Forward $37,091 $1,208 ($13) ($477) ($748) ($11) $37,049 Beginning Balance (3/31/2023) New Originations Net Advances/ Payments Prepayments Payoffs or Sales Other Ending Balance (6/30/2023) $30,000 $32,000 $34,000 $36,000 $38,000 $40,000 $ in millions 21 Footnotes: Payoffs or Sales includes $373 million in non-relationship loan sales and a corresponding reclassification of an additional $118 million to loans held for sale. Other includes purchase accounting accretion and amortization.

Loan and Lease Characteristics: Overall Portfolio and Q2 2023 Production Footnotes: Portfolio statistics and delinquencies as of June 30, 2023. Annualized net charge-off rate for Q2 2023. Loan-to-value (“LTV”), FICO, and debt service coverage (“DSC”) are based on weighted average for portfolio where data are available. LTV represents average LTV based on most recent appraisal against updated loan balance. Totals may not foot due to rounding. • Portfolio average loan size of $477,000 • 2Q23 average loan size of $519,000 • Portfolio average FICO of 761 and LTV of 62% • 2Q23 average FICO of 761 and LTV of 71% • Total delinquencies of 0.43% • Annualized net charge-off rate of 0.00% Non-owner Occupied CRE • Portfolio average loan size of $1.6 million • 2Q23 average loan size of $2.9 million • Portfolio average LTV of 52% and DSC of 1.90 • 2Q23 average LTV of 56% and DSC of 1.78 • Total delinquencies of 0.15% • Annualized net charge-off rate of 0.00% Commercial & Industrial • Portfolio average loan size of $687,000 • 2Q23 average loan size of $723,000 • Total delinquencies of 0.32% • Annualized net charge-off rate of 0.10% Multifamily • Portfolio average loan size of $2.3 million • 2Q23 average loan size of $2.3 million • Portfolio average LTV of 54% and DSC of 1.59 • 2Q23 average LTV of 43% and DSC of 1.72 • Total delinquencies of 0.00% • Annualized net charge-off rate of 0.00% Owner Occupied CRE • Portfolio average loan size of $982,000 • 2Q23 average loan size of $2.1 million • Portfolio average LTV of 56% • 2Q23 average LTV of 61% • Total delinquencies of 0.23% • Annualized net charge-off rate of 0.00% Lease & Equipment Finance (FinPac) • Portfolio average loan & lease size of $41,000 • 2Q23 average loan & lease size of $63,000 • Portfolio average yield: ~10% • Total delinquencies of 3.92% • Annualized net charge-off rate of 5.96% Puget Sound, 20% WA Other, 8% Portland Metro, 13% OR Other, 13% Bay Area, 7% Northern CA, 10% Southern CA, 15% Other, 14% Mortgage, 17% FinPac, 5% C&I, 21% Owner Occupied CRE, 14% Non-OO CRE, 17% Multifamily, 15% Other Loan Categories, 11% Portfolio Composition at June 30, 2023 Geographic Distribution at June 30, 2023 Mortgage 22

CRE and C&I Portfolio Composition Agriculture, 8.3% Contractors, 7.5% Finance/Insurance, 7.7% Manufacturing, 7.6% Professional, 4.6% Public Admin, 7.2% Rental & Leasing, 7.1% Retail, 2.5% Support Services, 3.7% Transportation/ Warehousing, 9.5% Wholesale, 6.6% Gaming, 5.6% Dentists, 7.6% Other Healthcare, 3.0% Other, 11.3% Office, 16.7% Multifamily, 33.1% Industrial, 15.4% Retail, 11.8% Special Purpose, 7.4% Hotel/Motel, 4.1% Other, 11.6% CRE Portfolio Composition (1) $17.3 Billion at June 30, 2023 C&I Portfolio Composition (1) $9.5 Billion at June 30, 2023 (1) CRE portfolio composition includes non-owner occupied term and owner occupied term balances as well as multifamily balances. C&I portfolio composition includes term, lines of credit & other, and leases & equipment finance balances. (2) Owner occupied and non-owner occupied disclosure relates to commercial real estate portfolio excluding multifamily loans. 45% Owner Occupied / 55% Non-Owner Occupied(2) Commercial Line Utilization was 32% at June 30, 2023 23

Office Portfolio Details Puget Sound, 22% WA Other, 5% Portland Metro, 12% OR Other, 15%Bay Area, 5% N. CA, 11% S. CA, 21% Other, 9% Office Portfolio Metrics at June 30, 2023 Average loan size $1.3 million Average LTV 57% DSC (non-owner occupied) 1.73x % with guaranty (by $ / by #) 84% / 82% Past due 30-89 days $0.8mm / 0.02% of office Nonaccrual $0.6mm / 0.02% of office Special mention $46mm / 1.53% of office Classified $16mm / 0.53% of office Number of Loans by Balance Geography 24 ■ Loans secured by office properties represented 8% of our total loan portfolio at June 30, 2023. ■ Our office portfolio is 40% owner- occupied, 57% non-owner-occupied, and 3% construction. Construction loans represent 22% of loans repricing in 2023. Excluding construction balances, only 18% of our office portfolio reprices over the next three years. ■ Properties located in suburban markets secure the majority of our office portfolio as only 6% of non-owner occupied office loans are located in downtown core business districts. ■ The average loan size in our office portfolio is $1.3 million, delinquencies are at a de minimis level, and the majority of our loans contain a guaranty. ■ Dental and other healthcare loans comprise 15% of our office portfolio. 1,746 441 71 38 7 6 <$1mm $1-5mm $5-10mm $10-20mm $20-30mm >$30mm 2023, 13% 2024, 4% 2025, 4% 2026 & After, 16% Fixed Rate*, 63% Repricing Schedule *Loans with a swap component are displayed as a fixed rate loan if the swap maturity is equal to the maturity of the loan. If the swap matures prior to the loan, the loan is displayed as adjustable with the rate resetting at the time of the swap maturity. 2023, 2% 2024, 5% 2025, 6% 2026 & After, 87% Maturity Schedule , 19 8 9 6 7

Allowance for Credit Losses (“ACL”) Footnotes: 1. Total includes $19.0 million for Reserve for Unfunded Commitments. 2. Total includes $19.8 million for Reserve for Unfunded Commitments. Allowance for Credit Losses by Loan Segment ($ in thousands) 3/31/2023 Q2 2023 Net (Charge-offs) Recoveries Reserve Build (Release) 6/30/2023 % of Loans and Leases Outstanding Commercial $125,423 ($1,951) ($23,130) $100,342 1.30 % Lease & Equipment Finance $120,104 ($25,574) $22,600 $117,130 6.73 % CRE $119,495 $35 $9,424 $128,954 0.67 % Residential/Home Equity $63,933 $59 $4,967 $68,959 0.84 % Consumer $7,538 ($646) $2,153 $9,045 4.78 % Total $436,493 ¹ ($28,077) $16,014 $424,430 ² 1.15 % % of loans and leases outstanding 1.18 % 1.15 % Remaining Credit Discount on Loans $106,584 $94,113 Total ACL Including Credit Discount $543,077 ¹ $518,543 ² % of loans and leases outstanding 1.46 % 1.40 % 25 Current Expected Credit Losses (“CECL”) Details ■ Provision expense of $16 million includes $15 million related to loans and leases and $1 million related to unfunded commitments. ■ The quarter’s provision expense reflects stabilizing credit trends in the FinPac portfolio; changes between the February 2023 and May 2023 economic forecasts; and portfolio mix changes, which include the reserve release associated with loan sales completed during the quarter, primarily in the commercial portfolio. ■ Key components of Moody’s May 2023 Baseline economic forecast include: ■ U.S. real GDP average annualized growth of 1.6% in 2023, 1.7% in 2024, 2.4% in 2025, and 2.7% in 2026. ■ U.S. unemployment rate average of 3.6% in 2023, 4.0% in 2024, 4.2% in 2025, and 4.1% in 2026. ■ The average federal funds rate is expected to be 4.9% in 2023, 4.3% in 2024, 3.2% in 2025, and 2.5% in 2026.

Credit Quality Pr ov is io n Ex pe ns e ($ in m ill io ns ) N on perform ing assets to total assets Provision Expense & Non-Performing Assets to Total Assets** $18.7 $27.6 $32.9 $17.1 $16.0 $88.4 0.15% 0.16% 0.18% 0.14% 0.15% Provision expense Initial Provision Non Performing Assets To Total Assets Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 $— $20.0 $40.0 $60.0 $80.0 $100.0 $120.0 —% 0.05% 0.10% 0.15% 0.20% 0.25% 0.30% 0.35% Cl as si fie d Lo an s / To ta l L oa ns Classified A ssets / RBC Classified Assets 0.75% 0.74% 0.73% 1.21% 1.13% 7.8% 7.9% 7.8% 15.0% 13.4% Classified Loans to Total Loans Classified Assets to Risk-Based Capital Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 —% 0.20% 0.40% 0.60% 0.80% 1.00% 1.20% 1.40% 1.60% —% 2.0% 4.0% 6.0% 8.0% 10.0% 12.0% 14.0% 16.0% A xi s Ti tle Net Charge-offs to Average Loans and Leases (annualized) 0.01% 0.02% 0.01% —% 0.03% 1.47% 1.36% 2.84% 3.89% 5.96% 0.11% 0.11% 0.19% 0.23% 0.30% Umpqua Bank (ex FinPac) FinPac Columbia Banking System, Inc. Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 —% 1.00% 2.00% 3.00% 4.00% 5.00% 6.00% 26 ■ If the remaining credit discount on loans of $94 million at June 30, 2023 is added to the ACL of $424 million at June 30, 2023, the ACL would increase to 1.40% of loans from the reported 1.15% level. ■ The increase in classified asset ratios between December 31, 2022 and March 31, 2023 relates to the addition of the historical Columbia portfolio and related purchase accounting adjustments and their impact on risk-based capital. The metrics are not reflective of any notable change in classified assets. A CL ($ in m ill io ns ) A CL / Total Loans and Leases Allowance for Credit Losses $274 $295 $315 $436 $424 $107 $94 1.12% 1.16% 1.21% ACL Credit Discount ACL to Total Loans and Leases ACL + Credit Discount to Total loans and Leases Q2 2022 Q3 2022 Q4 2022 Q1 2023 Q2 2023 $100 $200 $300 $400 $500 $600 $700 —% 0.20% 0.40% 0.60% 0.80% 1.00% 1.20% 1.40%$105.5 Footnotes: **Q 1 2023 provision expense of $105.5 million includes an initial provision of $88.4 million related to historical Columbia non-PCD loans. 1.46% 1.18% 1.15% 1.40%

Our Diversified Commercial Bank Business Model with a Strong Retail Presence Supports our Granular, High-Quality Deposit Base (1) Excludes public and brokered deposit balances. This is a non-GAAP financial measure. (2) Includes Reich & Tang Demand Deposit Marketplace program deposits of $623 million. Broker / Other, 6% Commercial, 49% Consumer, 39% Public, 6% June 30, 2023 Average consumer account balance $19 thousand Average commercial account balance $107 thousand Average customer account balance (1) $35 thousand Insured Cash Sweep (“ICS”) deposits (2) $3.2 billion Deposits in Certificate of Deposit Account Registry Service (“CDARS”) deposits $405 million Uninsured deposits as a % of total deposits 33% Non-interest, 39% Demand, 15% Money Market, 25% Savings, 8% Time, 13% Deposits by Type Deposits by Business Line 27 ■ Deposits were $41 billion at June 30, 2023 and represented by a largely granular base that is diversified by business line, industry, and geography. ■ Our deposit solutions, like ICS and CDARS, and our ability to collateralize select accounts, provide our customers with flexibility and improve the stability of our deposit base.

Capital Management 28 Common Equity Tier 1 ("CET1") Ratio 8.9% 0.3% (0.2)% 0.1% —% 9.1% 03/31/23 Adjusted net income ¹ Dividend on common stock RWA ² Merger-Related Items ³ 06/30/23 —% 2.5% 5.0% 7.5% 10.0% (1) Excludes PAA, CDI amortization, and merger-related expenses. (2) Also includes other slight adjustments. (3) Merger-related expenses and CDI amortization almost entirely offset income from PAA during the quarter. As merger expenses wind down, net merger-related items are expected to be additive to capital as income from PAA exceeds CDI amortization. Total Risk-Based Capital Ratio 10.9% 0.3% (0.2)% 0.1% —% 11.1% 03/31/23 Adjusted net income ¹ Dividend on common stock RWA ² Merger-Related Items ³ 06/30/23 —% 2.5% 5.0% 7.5% 10.0% 12.5% 7.2% 9.1% 9.1% 11.1% 6.0% 7.0% 8.5% 10.5% 1.2% 2.1% 0.6% 0.6% Capital Threshold ¹ Capital Above Threshold ² Tier 1 Leverage CET1 Tier 1 Risk-Based Total Risk-Based —% 2.0% 4.0% 6.0% 8.0% 10.0% 12.0% ■ Declared a quarterly cash dividend of $0.36 per common share on May 15, 2023, which was paid June 15, 2023. ■ We expect the quarterly net impact of purchase accounting to be highly accretive to earnings, as detailed on slides 5 and 8 of this presentation. This outlook supports our view that capital is likely to build rapidly. ■ We expect to quickly approach and exceed our long-term total risk-based capital target of 12%, providing for enhanced flexibility to return excess capital to shareholders while continuing to support our expanding franchise. We are already above our long-term CET1 capital target of 9%. Note: Regulatory capital ratios are estimates pending completion and filing of Columbia’s regulatory reports. (1) Capital Threshold is the greater of Regulatory Well-Capitalized Threshold or Capital Adequacy Threshold + Capital Conservation Buffer. (2) Capital Above Threshold is the level of capital above Columbia’s Regulatory Minimum, which is equivalent to the Capital Threshold.

APPENDIX Prior-Quarter Income Statement Component Details and Other Non-GAAP Reconciliation

Income Statement Component Details For the Quarter Ended March 31, 2023 LESS: EQUALS LESS: EQUALS ($ in thousands, except per-share data) GAAP Income Non-Operating Items (1) Operating Income (2) Merger-Related Items (3) Adjusted Operating Income (2) Interest income $475,951 $— $475,951 $31,895 $444,056 Interest expense 101,253 — 101,253 (150) 101,403 Net interest income 374,698 — 374,698 31,745 342,953 Provision for credit losses 105,539 — 105,539 88,427 17,112 Net interest income after provision 269,159 — 269,159 (56,682) 325,841 Non-interest income 54,735 8,074 46,661 — 46,661 Non-interest expense 342,818 117,189 225,629 12,660 212,969 Income before provision for income taxes (18,924) (109,115) 90,191 (69,342) 159,533 Provision for income taxes (4,886) (23,565) 18,679 (17,336) 36,015 Net income ($14,038) ($85,550) $71,512 ($52,006) $123,518 Revenue $429,433 $8,074 $421,359 $31,745 $389,614 Pre-provision net revenue (2) $86,615 ($109,115) $195,730 $19,085 $176,645 Net interest margin (4) 4.08 % NA 4.08 % 0.35 % 3.73 % Efficiency ratio (4) 79.71 % 26.25 % 53.46 % (1.11) % 54.57 % PPNR return on assets (2), (4) 0.89 % (1.12) % 2.01 % 0.19 % 1.82 % Return on assets (0.14) % (0.88) % 0.74 % (0.53) % 1.27 % Return on equity (1.70) % (10.36) % 8.66 % (6.29) % 14.95 % Return on tangible common equity (2) (2.09) % (12.73) % 10.64 % (7.73) % 18.37 % Earnings per share, diluted ($0.09) ($0.55) $0.46 ($0.33) $0.79 30 Notable Merger Items ■ Results include one month of the combined company’s operations. ■ GAAP results were significantly impacted by non-operating and merger-related items in the quarter. Excluding these items, adjusted operating EPS was $0.79, return on assets was 1.27%, and return on tangible common equity was 18.4%. ■ Merger-related expenses (captured in non-operating items) and the initial provision (captured in merger-related items) reduced EPS by $1.01. Footnotes: All dollar values exclude tax equivalent adjustments; all ratios, where relevant, include this adjustment. (1) Non-operating income and expense items are detailed in the Appendix. Non-operating expense includes $116 million of merger-related expenses. (2) All items in this column represent non-GAAP financial measures and should be reviewed alongside the GAAP reconciliation in this table. PPNR, PPNR return on assets, and return on tangible common equity are also non-GAAP measures for all ratios presented, including those in the GAAP column; a reconciliation is provided in the Appendix. (3) Merger-related items include purchase accounting accretion and amortization captured in interest income and interest expense, the initial provision of $88 million, and CDI amortization of $13 million. (4) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate and is included in the calculation of this ratio.

Non-GAAP Reconciliation: Tangible Capital ($ in thousands, except per-share data) Jun 30, 2023 Mar 31, 2023 Dec 31, 2022 Sep 30, 2022 Jun 30, 2022 Total shareholders' equity a $4,828,188 $4,884,723 $2,479,826 $2,417,514 $2,518,276 Less: Goodwill 1,029,234 1,030,142 — — — Less: Other intangible assets, net 666,762 702,315 4,745 5,764 6,789 Tangible common shareholders’ equity b 3,132,192 3,152,266 2,475,081 2,411,750 2,511,487 Less: Accumulated other comprehensive (loss) income (AOCI) (418,762) (300,134) (426,864) (449,560) (308,147) Tangible common shareholders’ equity, ex AOCI c $3,550,954 $3,452,400 $2,901,945 $2,861,310 $2,819,634 Total assets d $53,592,096 $53,994,226 $31,848,639 $31,471,960 $30,135,694 Less: Goodwill 1,029,234 1,030,142 — — — Less: Other intangible assets, net 666,762 702,315 4,745 5,764 6,789 Tangible assets e $51,896,100 $52,261,769 $31,843,894 $31,466,196 $30,128,905 Common shares outstanding at period end f 208,514 208,429 129,321 129,320 129,318 Total shareholders' equity to total assets ratio a / d 9.01 % 9.05 % 7.79 % 7.68 % 8.36 % Tangible common equity ratio b / e 6.04 % 6.03 % 7.77 % 7.66 % 8.34 % Tangible common equity ratio, ex AOCI c / e 6.84 % 6.61 % 9.11 % 9.09 % 9.36 % Book value per common share (1) a / f $23.16 $23.44 $19.18 $18.69 $19.47 Tangible book value per common share (1) b / f $15.02 $15.12 $19.14 $18.65 $19.42 Tangible book value per common share, ex AOCI (1) c / f $17.03 $16.56 $22.44 $22.13 $21.80 Footnotes: (1) Prior periods have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958. 31

Non-GAAP Reconciliation Footnotes: (1) Tax exempt interest has been adjusted to a taxable equivalent basis using a 21% tax rate. For the Quarter Ended ($ in thousands) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Net interest income (1) c $ 485,168 $ 375,369 $ 305,762 $ 287,933 $ 248,522 Non-interest income (GAAP) d $ 39,678 $ 54,735 $ 34,879 $ 29,445 $ 55,235 Less: non-interest income adjustments a 16,252 (8,074) 8,115 22,575 (951) Operating non-interest income (non-GAAP) e $ 55,930 $ 46,661 $ 42,994 $ 52,020 $ 54,284 Revenue (GAAP) f $ 524,846 $ 430,104 $ 340,641 $ 317,378 $ 303,757 Operating revenue (non-GAAP) g $ 541,098 $ 422,030 $ 348,756 $ 339,953 $ 302,806 Non-interest expense (GAAP) h $ 328,559 $ 342,818 $ 194,982 $ 177,964 $ 179,574 Less: non-interest expense adjustments b (31,768) (117,189) (13,603) (2,133) (3,114) Operating non-interest expense (non-GAAP) i $ 296,791 $ 225,629 $ 181,379 $ 175,831 $ 176,460 Net (loss) income (GAAP) j $ 133,377 $ (14,038) $ 82,964 $ 84,040 $ 78,591 (Benefit) provision for income taxes 45,703 (4,886) 29,464 27,473 26,548 (Loss) income before provision for income taxes 179,080 (18,924) 112,428 111,513 105,139 Provision for credit losses 16,014 105,539 32,948 27,572 18,692 Pre-provision net revenue (PPNR) (non-GAAP) k 195,094 86,615 145,376 139,085 123,831 Less: Non-interest income adjustments a 16,252 (8,074) 8,115 22,575 (951) Add: Non-interest expense adjustments b 31,768 117,189 13,603 2,133 3,114 Operating PPNR (non-GAAP) l $ 243,114 $ 195,730 $ 167,094 $ 163,793 $ 125,994 Net income (GAAP) j $ 133,377 $ (14,038) $ 82,964 $ 84,040 $ 78,591 Less: Non-interest income adjustments a 16,252 (8,074) 8,115 22,575 (951) Add: Non-interest expense adjustments b 31,768 117,189 13,603 2,133 3,114 Tax effect of adjustments (11,981) (23,565) (5,459) (6,116) (480) Operating net income (non-GAAP) m $ 169,416 $ 71,512 $ 99,223 $ 102,632 $ 80,274 For the Quarter Ended ($ in thousands) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Non-Interest Income Adjustments Gain (loss) on equity securities, net $ (697) $ 2,416 $ 284 $ (2,647) $ (2,075) (Loss) gain on swap derivatives 1,288 (3,543) (2,329) 4,194 7,337 Change in fair value of certain loans held for investment (6,965) 9,488 4,192 (26,397) (15,210) Change in fair value of MSR due to valuation inputs or assumptions (2,242) (2,937) (9,914) 16,403 10,899 MSR hedge gain (loss) (7,636) 2,650 (348) (14,128) — Total non-interest income adjustments a $ (16,252) $ 8,074 $ (8,115) $ (22,575) $ 951 Non-Interest Expense Adjustments Merger related expenses $ 29,649 $ 115,898 $ 11,637 $ 769 $ 2,672 Exit and disposal costs 2,119 1,291 1,966 1,364 442 Total non-interest expense adjustments b $ 31,768 $ 117,189 $ 13,603 $ 2,133 $ 3,114 32

Non-GAAP Reconciliation (cont.) For the Quarter Ended ($ in thousands, except per-share data) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Select Per-Share & Performance Metrics Earnings-per-share - basic (1) j/r $ 0.64 $ (0.09) $ 0.64 $ 0.65 $ 0.61 Earnings-per-share - diluted (1) j/s $ 0.64 $ (0.09) $ 0.64 $ 0.65 $ 0.61 Efficiency ratio h/f 62.60 % 79.71 % 57.24 % 56.07 % 59.12 % Return on average assets j/n 1.00 % (0.14) % 1.04 % 1.09 % 1.04 % Return on average tangible assets j/o 1.03 % (0.15) % 1.04 % 1.09 % 1.04 % PPNR return on average assets k/n 1.46 % 0.89 % 1.82 % 1.80 % 1.64 % Return on average common equity j/p 10.84 % (1.70) % 13.50 % 12.99 % 12.20 % Return on average tangible common equity j/q 16.63 % (2.09) % 13.53 % 13.02 % 12.23 % Operating Per-Share & Performance Metrics Operating earnings-per-share - basic (1) m/r $ 0.81 $ 0.46 $ 0.77 $ 0.79 $ 0.62 Operating earnings-per-share - diluted (1) m/s $ 0.81 $ 0.46 $ 0.76 $ 0.79 $ 0.62 Operating efficiency ratio i/g 54.85 % 53.46 % 52.01 % 51.72 % 58.27 % Operating return on average assets m/n 1.27 % 0.74 % 1.24 % 1.33 % 1.06 % Operating return on average tangible assets m/o 1.31 % 0.75 % 1.24 % 1.33 % 1.06 % Operating PPNR return on average assets l/n 1.82 % 2.01 % 2.10 % 2.12 % 1.66 % Operating return on average common equity m/p 13.77 % 8.66 % 16.14 % 15.86 % 12.46 % Operating return on average tangible common equity m/q 21.13 % 10.64 % 16.18 % 15.90 % 12.49 % For the Quarter Ended ($ in thousands) Q2 2023 Q1 2023 Q4 2022 Q3 2022 Q2 2022 Average Assets n $ 53,540,574 $ 39,425,975 $ 31,637,490 $ 30,668,177 $ 30,356,903 Less: Average goodwill and other intangible assets, net 1,718,705 623,042 5,298 6,343 7,379 Average tangible assets o $ 51,821,869 $ 38,802,933 $ 31,632,192 $ 30,661,834 $ 30,349,524 Average common shareholders’ equity p $ 4,935,239 $ 3,349,761 $ 2,438,639 $ 2,567,266 $ 2,584,836 Less: Average goodwill and other intangible assets, net 1,718,705 623,042 5,298 6,343 7,379 Average tangible common equity q $ 3,216,534 $ 2,726,719 $ 2,433,341 $ 2,560,923 $ 2,577,457 Weighted average basic shares outstanding (1) r 207,977 156,383 129,321 129,319 129,306 Weighted average diluted shares outstanding (1) s 208,545 156,383 129,801 129,733 129,673 Footnotes: (1) Prior periods have been restated as a result of the adjustment to common shares outstanding based on the exchange ratio from the UHC merger of 0.5958. 33


Washington	000-20288	91-1422237
(State or Other Jurisdiction of Incorporation or Organization)	(Commission File Number)	(I.R.S. Employer Identification Number)


TITLE OF EACH CLASS	TRADING SYMBOL	NAME OF EXCHANGE
Common Stock, No Par Value	COLB	The NASDAQ Stock Market LLC


Item 9.01			Financial Statements and Exhibits.
(d)			EXHIBITS
			99.1 Press Release announcing second quarter 2023 financial results dated July 19, 2023
			99.2 Second Quarter 2023 Investor Presentation
			104 Cover Page Interactive Data File (embedded within the Inline XBRL document)


			Columbia Banking System, Inc. (Registrant)

Dated: July 19, 2023			By: /s/ Ronald L. Farnsworth Ronald L. Farnsworth Executive Vice President/Chief Financial Officer


Item 7.01			Regulation FD Disclosure.