BANNER CORP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED March 31, 2026

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM ______________ to ______________

Commission File Number 000-26584

BANNER CORPORATION

(Exact name of registrant as specified in its charter)

10 South First Avenue, Walla Walla, Washington 99362

(Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (509)527-3636

Securities registered pursuant to Section 12(b) of the Act

All references to “Banner” refer to Banner Corporation and those to the “Bank” refer to its wholly-owned subsidiary, Banner Bank. As used throughout this report, the terms “we,” “our,” “us,” or the “Company” refer to Banner Corporation and its consolidated subsidiaries, unless the context otherwise requires.

Special Note Regarding Forward-Looking Statements

Certain matters in this Form 10-Q constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include statements with respect to our beliefs, plans, objectives, goals, expectations, assumptions and statements about future economic performance and projections of financial items, including statements about our financial condition, liquidity and results of operations. Forward-looking statements are not statements of historical fact, are based on certain assumptions and are generally identified by use of the words “believes,” “expects,” “anticipates,” “estimates,” “forecasts,” “intends,” “plans,” “targets,” “potentially,” “probably,” “projects,” “outlook” or similar expressions, or future or conditional verbs such as “may,” “will,” “should,” “would” and “could.” Forward-looking statements are inherently subject to numerous risks and uncertainties, including ongoing market volatility and evolving global conditions, which may cause actual results to differ materially from those expressed or implied. These factors include, but are not limited to:

•Adverse impacts to economic conditions in our local market areas, other markets where the Company has lending relationships, or other aspects of the Company’s business operations or financial markets, including, without limitation, as a result of labor shortages, elevated inflation, recessionary pressures, or slowing economic growth;

•Changes in interest rate levels and volatility, and the timing and pace of such changes, including actions by the Federal Reserve, which could materially affect our net interest margin, funding costs, asset values, access to capital and liquidity;

•The impact of inflation and related monetary and fiscal policy responses, and their impact on consumer and business behavior;

•Geopolitical developments and international conflicts, or the imposition of new or increased tariffs and trade restrictions, which may disrupt financial markets, global supply chains, commodity prices, or economic activity in specific industry sectors, including, but not limited to, agriculture-based lending;

•The effects of a federal government shutdown, a debt ceiling standoff, or other fiscal policy uncertainty;

•The impact of bank failures or adverse developments at other banks and related negative publicity about the banking industry on investor and depositor sentiment;

•Expectations regarding our key growth initiatives and strategic priorities;

•Credit risks from lending activities, including changes in the level and direction of loan delinquencies and write-offs and changes in estimates of the adequacy of the allowance for credit losses, which could necessitate additional provisions for credit losses, resulting from both loans originated and loans acquired from other financial institutions;

•Results of examinations by regulatory authorities, which could result in the imposition of penalties, required changes to our business practices, or additional reserves;

•Competitive pressures among depository and non-depository institutions that may contribute to industry disintermediation or adversely affect pricing, market share, deposit flows or product offerings;

•Fluctuations in real estate values;

•The ability to adapt to rapid technological changes, including advancements in artificial intelligence, digital banking platforms, and cybersecurity;

•Ability to access cost-effective funding and to control operating costs and expenses;

•Vulnerabilities in information systems or third-party service providers, including disruptions, breaches, or attacks;

•Market volatility or deterioration in capital markets affecting liquidity, valuations, or investor confidence;

•The costs, effects and outcomes of litigation or other legal proceedings involving the Company;

•Legislation or regulatory changes, including but not limited to shifts in capital requirements, banking regulation, tax laws, or consumer protection laws;

•Changes in accounting principles, policies or guidelines;

•The impact of future acquisitions or business combinations, in addition to goodwill impairment risks and integration challenges;

•The effects of critical accounting policies and judgments, including the use of estimates in determining fair value of certain of our assets and liabilities, which estimates may prove to be inaccurate;

•Effects on loan collateral, operations, or compliance obligations from climate change, severe weather, natural disasters, pandemics, public health crises, acts of war or terrorism, civil unrest and other external events;

•Other economic, competitive, governmental, regulatory, and technological factors affecting our operations, pricing, products and services; and

•Other risks detailed in our Form 10-K for the year ended December 31, 2025 (“2025 Form 10-K”), or in our reports filed with or furnished to the U.S. Securities and Exchange Commission (SEC), including this Form 10-Q.

Any forward-looking statements are based upon Management’s beliefs and assumptions at the time they are made. We do not undertake and specifically disclaim any obligation to update any forward-looking statements included in this report or the reasons why actual results could differ from those contained in such statements, whether as a result of new information, future events or otherwise. In light of these risks, uncertainties and assumptions, the forward-looking statements discussed in this report might not occur, and you should not put undue reliance on any forward-looking statements.