Results of Operations · Reg FD Disclosure

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): April 23, 2026 _______________________ (Exact name of registrant as specified in its charter) _______________________ California 0-10661 94-2792841 (State or other jurisdiction of incorporation or organization) (Commission File No.) (I.R.S. Employer Identification No.) 63 Constitution Drive Chico, California 95973 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: ( 530 )  898-0300 _____________________ 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 (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, no par value TCBK Nasdaq 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. ☐ Item 2.02    Results of Operations and Financial Condition On April 23, 2026, TriCo Bancshares (the "Company") announced its unaudited financial results as of and for the three months ended March 31, 2026. A copy of the press release is attached as Exhibit 99.1 to this to this Form 8-K and is incorporated herein by reference. Item 7.01    Regulation FD Disclosure The executive officers of the Company intend to use the materials filed herewith, in whole or in part, in one or more presentations, discussions or meetings with investors. A copy of the investor presentation is attached hereto as Exhibit 99.2. Item 9.01    Financial Statements and Exhibits (d) Exhibits 99.1     Press release dated April 23, 2026 99. 2     Investor Presentation 104    Cover Page Interactive Data File (embedded within the Inline XBRL document). The information furnished under Item 2.02, Item 7.01, and Item 9.01 of this Current Period on Form 8-K, including the exhibit, shall not be deemed “filed” for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, or otherwise subject to the liabilities under that Section, nor shall it be deemed incorporated by reference in any registration statement or other filings of TriCo Bancshares under the Securities Act of 1933, as amended, except as shall be set forth by specific reference in such filing. 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 thereunto duly authorized. TRICO BANCSHARES Date: April 23, 2026 /s/ Peter G. Wiese Peter G. Wiese, Executive Vice President and Chief Financial Officer (Principal Financial and Accounting Officer)