COLB · Columbia Banking System, Inc.

$208 million $217 million $0.73 $0.76 Net income Operating net income1 Earnings per common share - diluted Operating earnings per common share - diluted1 CEO Commentary "Our second quarter results demonstrate the resilience of our franchise and reflect the value of disciplined execution across the company," said Clint Stein, Chairman, CEO & President. "While the operating environment remains dynamic, we continued to execute on our strategic priorities through prudent expense management, ongoing balance sheet optimization, and consistent capital returns to shareholders. Commercial loan balances continued to grow, reflecting the strength of our customer relationships and the trust we have built across our markets. We also continued to reposition the balance sheet in ways that support stronger long-term performance. Supported by our diversified business model, sound credit culture, and strong capital generation, we remain committed to delivering sustainable returns and creating

$192 million $209 million $0.66 $0.72 Net income Operating net income1 Earnings per common share - diluted Operating earnings per common share - diluted1 CEO Commentary "Our first quarter results reflect continued execution against the priorities we have previously outlined: delivering sustainable performance, strengthening our balance sheet, and returning excess capital to shareholders," said Clint Stein, Chair, CEO & President. "During the quarter, we increased capital returns, reflecting our confidence in earnings durability and ongoing capital generation. We also made further progress optimizing our balance sheet, as commercial loan growth and muted seasonal deposit trends contributed to the profitable remix of assets and liabilities, positioning Columbia for attractive returns over time. At the same time, our credit performance continues to benefit from disciplined underwriting and our diversified, relationship-based loan portfolio that is performing as designed. With these

$215 million $243 million $0.72 $0.82 Net income Operating net income1 Earnings per common share - diluted Operating earnings per common share - diluted1 CEO Commentary "Our fourth quarter performance marked a strong end to a tremendous year for Columbia, reflecting continued momentum across our businesses and our commitment to consistent, repeatable results," said Clint Stein, President and CEO. "Our operating performance was supported by disciplined balance sheet management, new and expanding customer relationships, and the first full-quarter contribution from Pacific Premier. We remain on track for a seamless systems conversion later this quarter, which will enable us to fully realize deal- related cost savings and achieve a clean expense run rate by the third quarter. Investments made throughout 2025 strengthened our western footprint and enhanced our long-term earnings power, and we entered 2026 with healthy pipelines, solid capital generation, and a clear path to continued