8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): March 12, 2026

CALUMET, INC.

(Exact name of registrant as specified in its charter)

1060 N Capitol Ave

Suite 6-401

Indianapolis, Indiana 46204

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code (317) 328-5660

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities Registered Pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On March 12, 2026, Calumet, Inc. (the “Company”) announced that, subject to market conditions, its wholly owned subsidiaries, Calumet Specialty Products Partners, L.P. (the “Partnership”) and Calumet Finance Corp. (together with the Partnership, the “Issuers”), intend to offer $150.0 million in aggregate principal amount of the Issuers’ 9.75% Senior Notes due 2031 (the “Additional Notes”) in a private placement to eligible purchasers (the “Tack-on Offering”). In connection with the Tack-on Offering, the Company is providing certain information regarding the Company to prospective investors in a preliminary offering memorandum, dated March 12, 2026, and such information is furnished as Exhibit 99.1 hereto. The Company intends to use the net proceeds from the Tack-on Offering to repay borrowings outstanding under the Company’s revolving credit facility. The Additional Notes will constitute a further issuance of the Issuers’ 9.75% Senior Notes due 2031, of which $405.0 million in aggregate principal amount were issued on January 12, 2026 (the “Existing Notes”). The Additional Notes will form a single series with, and have the same terms (other than the initial offering price) as, the Existing Notes.

In accordance with General Instruction B.2 of Form 8-K, the information contained in this Item 7.01, including Exhibit 99.1, shall not be deemed “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such information and Exhibit 99.1 be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

On March 12, 2026, the Company issued a press release, a copy of which is attached hereto as Exhibit 99.2 and incorporated herein by reference, announcing the Tack-on Offering.

The press release attached hereto as Exhibit 99.2 shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any jurisdiction in which the offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such jurisdiction. The Additional Notes will not be registered under the Securities Act or any state securities law and may not be offered or sold in the United States absent registration or an applicable exemption from registration under the Securities Act and applicable state securities laws.

This Current Report on Form 8-K includes “forward-looking statements” within the meaning of federal securities laws. Such forward-looking statements are subject to a number of risks and uncertainties, many of which are beyond the Company’s control. All statements, other than historical facts included in this Current Report on Form 8-K, are forward-looking statements. All forward-looking statements speak only as of the date of this Current Report on Form 8-K. Although the Company believes that the plans, intentions and expectations reflected in or suggested by the forward-looking statements are reasonable, there is no assurance that these plans, intentions or expectations will be achieved. Therefore, actual outcomes and results could materially differ from what is expressed, implied or forecast in such statements.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

EX-99.1

Exhibit 99.1

Tenth Amendment to the Third Amended and Restated Credit Agreement

Prior to the closing of the recently announced notes offering (the “Offering”), we intend to enter into the Tenth Amendment to the Third Amended and Restated Credit Agreement (the “Tenth Amendment”). The Tenth Amendment is expected to modify the Third Amended and Restated Credit Agreement, dated as of February 23, 2018 (the “Credit Agreement”), by and among Calumet GP, LLC, Calumet Specialty Products Partners, L.P., certain of our subsidiaries party thereto, the lenders party thereto and Bank of America, N.A., as administrative agent, to permit the issuance of, and the incurrence of indebtedness in connection with, the notes being offered. As of the date hereof, we have obtained the consent from the requisite number of lenders under the Credit Agreement to enter into the Tenth Amendment. The Offering is conditioned on our entry into the Tenth Amendment.

EX-99.2

Exhibit 99.2

Calumet Announces $150 Million Private Placement of Additional 9.75% Senior Notes due 2031

INDIANAPOLIS, March 12, 2026 /PRNewswire/ — Calumet, Inc. (NASDAQ: CLMT) (the “Company” or “Calumet”) today announced that, subject to market conditions, its wholly owned subsidiaries, Calumet Specialty Products Partners, L.P. (the “Partnership”) and Calumet Finance Corp. (together with the Partnership, the “Issuers”), intend to offer (the “Offering”) for sale to eligible purchasers in a private placement under Rule 144A and Regulation S under the Securities Act of 1933, as amended (the “Securities Act”), $150 million in aggregate principal amount of 9.75% Senior Notes due 2031 (the “Additional Notes”). Calumet intends to use the net proceeds from the Offering to repay outstanding borrowings under Calumet’s revolving credit facility.

The Additional Notes will constitute a further issuance of the Issuers’ 9.75% Senior Notes due 2031, of which $405 million in aggregate principal amount were issued on January 12, 2026 (the “Existing Notes”). The Additional Notes will form a single series with, and have the same terms (other than the initial offering price) as, the Existing Notes.

The securities to be offered will not be, and have not been, registered under the Securities Act, or any state securities laws, and unless so registered, the securities may not be offered or sold in the United States except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and applicable state securities laws. Calumet plans to offer and sell the securities only to persons reasonably believed to be qualified institutional buyers pursuant to Rule 144A under the Securities Act and to non-U.S. persons outside the United States pursuant to Regulation S under the Securities Act.

This press release shall not constitute an offer to sell, or the solicitation of an offer to buy, any of these securities, nor shall there be any sale of these securities in any jurisdiction in which such offer, solicitation, or sale would be unlawful. This press release is being issued pursuant to and in accordance with Rule 135c under the Securities Act.

About Calumet

Calumet, Inc. (NASDAQ: CLMT) manufactures, formulates and markets a diversified slate of specialty branded products and renewable fuels to customers across a broad range of consumer-facing and industrial markets. Calumet is headquartered in Indianapolis, Indiana and operates twelve facilities throughout North America.

Cautionary Statement Regarding Forward-Looking Statements

Certain statements and information in this press release may constitute “forward-looking statements.” The words “will,” “may,” “intend,” “believe,” “expect,” “outlook,” “forecast,” “anticipate,” “estimate,” “continue,” “plan,” “should,” “could,” “would,” or other similar expressions are intended to identify forward-looking statements, which are generally not historical in nature. The statements discussed in this press release that are not purely historical data are forward-looking statements, including, but not limited to, the statements regarding the

Offering and the use of proceeds therefrom. These forward-looking statements are based on our current expectations and beliefs concerning future developments and their potential effect on us. While our management considers these assumptions to be reasonable, they are inherently subject to significant business, economic, competitive, regulatory and other risks, contingencies and uncertainties, most of which are difficult to predict and many of which are beyond our control. Accordingly, our actual results may differ materially from the future performance that we have expressed or forecast in our forward-looking statements. For additional information regarding known material risks, uncertainties and other factors that can affect future results, please see our filings with the Securities and Exchange Commission (“SEC”), including the risk factors and other cautionary statements in the latest Annual Report on Form 10-K of the Company and other filings with the SEC by the Company. We undertake no obligation to publicly update or revise any forward-looking statements after the date they are made, whether as a result of new information, future events or otherwise, except to the extent required by applicable law.

SOURCE Calumet, Inc.

For further information: Investors: John Kompa 317-957-5237; Public Relations: Media Oakes 317-957-5319

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