COLUMBIA BANKING SYSTEM, INC. REPORTS SECOND QUARTER 2025 RESULTS

Organizational Update
Columbia Banking System, Inc. ("Columbia," the "Company," "we," or "our") continues to plan for its acquisition of Pacific Premier Bancorp, Inc. ("Pacific Premier"), which was announced on April 23, 2025. The shareholders of both companies overwhelmingly approved the combination at their respective special meetings, which were held July 21, 2025. We anticipate closing the transaction as soon as September 1, 2025, pending regulatory approvals and satisfaction of other customary closing conditions. Integration efforts are progressing as planned, driven by the comprehensive preparation of cross-company teams, which are led by Columbia's Integration Management Office, positioning us for a smooth and timely closing once regulatory approvals are secured and other customary closing conditions are satisfied.

Columbia expanded its Arizona footprint with the opening of its second branch in Phoenix and its first in Mesa, bringing the total number of branches in the state to four. We also opened a branch in Eastern Oregon, restoring essential banking services to a bank-less rural community. Our branch strategy encompasses thriving metropolitan areas and core community markets alike, supporting bankers already serving customers in our markets and strengthening opportunities to bring new relationships to Columbia.

Net Interest Income
Net interest income was $446 million for the second quarter of 2025, up $21 million from the prior quarter. The increase reflects higher interest income earned on loans and investment securities and relatively stable funding costs.

Columbia's net interest margin was 3.75% for the second quarter of 2025, up 15 basis points from the first quarter of 2025. Net interest margin benefited from an increase in the yield on taxable investment securities to 4.22% for the second quarter of 2025, up from 3.72% for the first quarter of 2025. The increase is due to higher conditional prepayment rates ("CPR") and the purchase of higher-yielding investment securities during the quarter. The average yield on the loan portfolio increased by 8 basis points between periods to 6.00% for the second quarter of 2025, due primarily to higher yields on commercial and construction loans and a $2 million interest recovery related to a nonperforming loan that repaid in full. The cost of interest-bearing deposits was unchanged between periods at 2.52% for the second quarter of 2025, in line with the cost of interest-bearing deposits for the month of June and as of June 30, 2025. Columbia's cost of interest-bearing liabilities decreased 2 basis points from the prior quarter to 2.78% for the second quarter of 2025, in line with the cost of interest-bearing liabilities for the month of June and as of June 30, 2025. Please refer to the Q2 2025 Earnings Presentation for additional net interest margin change details and interest rate sensitivity information.

Non-interest Income
Non-interest income was $64 million for the second quarter of 2025, down $2 million from the prior quarter. The decrease was driven by quarterly changes in fair value adjustments and mortgage servicing rights ("MSR") hedging activity, due to interest rate fluctuations during the quarter, collectively resulting in a net fair value loss of $1 million in the second quarter compared to a net fair value gain of $9 million in the first quarter, as detailed in our non-GAAP disclosures. Excluding these items, non-interest income was up $8 million[2] between periods, due primarily to higher card-based fee income and growth in other core fee-generating businesses, including swap-related income, financial services and trust revenue, and treasury management fees.

Non-interest Expense
Non-interest expense was $278 million for the second quarter of 2025, down $62 million from the prior quarter, which included a $55 million accrual related to a legal settlement and $15 million in severance expense. Excluding the legal settlement, exit and disposal costs, and merger and restructuring expense, which includes the first quarter's severance expense, non-interest expense was $269 million², down $1 million from the prior quarter, as lower legal expense—which was separate from the legal settlement—intangible amortization, and other miscellaneous expenses more than offset an increase in compensation costs. Please refer to the Q2 2025 Earnings Presentation for additional expense details.

Balance Sheet
Total consolidated assets were $51.9 billion as of June 30, 2025, up from $51.5 billion as of March 31, 2025. Cash and cash equivalents were $1.9 billion as of June 30, 2025, down from $2.1 billion as of March 31, 2025. Including secured off-balance sheet lines of credit, total available liquidity was $18.6 billion as of June 30, 2025, representing 36% of total assets, 44% of total deposits, and 132% of uninsured deposits. Available-for-sale securities, which are held on balance sheet at fair value, were $8.7 billion as of June 30, 2025, an increase of $424 million relative to March 31, 2025, as purchases and an increase in the fair value of the portfolio offset paydowns. Please refer to the Q2 2025 Earnings Presentation for additional details related to our securities portfolio and liquidity position.

Gross loans and leases were $37.6 billion as of June 30, 2025, an increase of $21 million relative to March 31, 2025. The change primarily reflects 2% annualized growth in commercial and owner-occupied commercial real estate loans, which was offset by 7% annualized contraction in multifamily loans. "Our teams remain focused on relationship-driven activity as we continue to let transactional real estate portfolios wind down," commented Chris Merrywell, President of Columbia Bank. "Loan balances were also impacted by an increase in prepayment activity, which muted a double-digit increase in origination volume relative to both the prior and year-ago quarters." Please refer to the Q2 2025 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 $41.7 billion as of June 30, 2025, a decrease of $475 million relative to March 31, 2025, as customer deposits declined due to seasonal tax payments and other customer cash usage. "We experienced customer deposit contraction in April following strong customer balance growth in March," stated Mr. Merrywell. "Seasonal balance declines were accompanied by customers' usage of cash to pay down debt, which impacted loan prepayment activity. The quarter's results also reflect deposit balances moving off balance sheet into our wealth management products, which enhances our core fee income generation as we provide our customers with needs-based solutions." Borrowings were $3.4 billion as of June 30, 2025, an increase of $800 million relative to March 31, 2025. Please refer to the Q2 2025 Earnings Presentation for additional details related to deposit characteristics and flows.

Credit Quality
The allowance for credit losses was $439 million, or 1.17% of loans and leases, as of June 30, 2025, unchanged from March 31, 2025. The provision for credit losses was $29 million for the second quarter of 2025 and reflects credit migration trends, charge-off activity, and changes in the economic forecasts used in credit models.

Net charge-offs were 0.31% of average loans and leases (annualized) for the second quarter of 2025, compared to 0.32% for the first quarter of 2025. Net charge-offs in the FinPac portfolio were $14 million in the second quarter, compared to $17 million in the first quarter. Net charge-offs excluding the FinPac portfolio were $15 million in the second quarter, compared to $13 million in the first quarter. Non-performing assets were $180 million, or 0.35% of total assets, as of June 30, 2025, compared to $178 million, or 0.35% of total assets, as of March 31, 2025. Please refer to the Q2 2025 Earnings Presentation for additional details related to the allowance for credit losses and other credit trends.

Capital
Columbia's book value per common share was $25.41 as of June 30, 2025, compared to $24.93 as of March 31, 2025. The increase reflects net capital generation and a favorable change in accumulated other comprehensive (loss) income ("AOCI") to $(334) million as of June 30, 2025, compared to $(358) million as of the prior quarter-end. The change in AOCI is due primarily to a decrease in the tax-effected net unrealized loss on available-for-sale securities to $311 million as of June 30, 2025, compared to $337 million as of March 31, 2025. Tangible book value per common share³ was $18.47 as of June 30, 2025, compared to $17.86 as of March 31, 2025.

Columbia's estimated total risk-based capital ratio was 13.0%, and its estimated common equity tier 1 risk-based capital ratio was 10.8% as of June 30, 2025, compared to 12.9% and 10.6%, respectively, as of March 31, 2025. Columbia remains above current "well-capitalized" regulatory minimums. The regulatory capital ratios as of June 30, 2025 are estimates, pending completion and filing of Columbia's regulatory reports. 

Earnings Presentation and Conference Call Information
Columbia's Q2 2025 Earnings Presentation provides additional disclosure. A copy will be available on our investor relations page: www.columbiabankingsystem.com.

Columbia will host its second quarter 2025 earnings conference call on July 24, 2025 at 2:00 p.m. PT (5:00 p.m. ET). During the call, Columbia's management will provide an update on recent activities and discuss its second quarter 2025 financial results. Participants may join the audiocast or register for the call using the link below to receive dial-in details and their own unique PINs. It is recommended you join 10 minutes prior to the start time.

Join the audiocast: https://edge.media-server.com/mmc/p/skhq48of/

Register for the call: https://register-conf.media-server.com/register/BI5727811477e9400984084cc006a83205

Access the replay through Columbia's investor relations page: https://www.columbiabankingsystem.com/news-market-data/event-calendar/default.aspx

About Columbia Banking System, Inc.
Columbia (Nasdaq: COLB) is headquartered in Tacoma, Washington and is the parent company of Columbia Bank (dba: Umpqua Bank), an award-winning western U.S. regional bank. Columbia Bank is the largest bank headquartered in the Northwest and one of the largest banks headquartered in the West with locations in Arizona, California, Colorado, Idaho, Nevada, Oregon, Utah, and Washington. With over $50 billion of assets, Columbia Bank combines the resources, sophistication, and expertise of a national bank with a commitment to deliver superior, personalized service. The bank 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. Columbia Bank customers also have access to comprehensive investment and wealth management expertise as well as healthcare and private banking through Columbia Wealth Advisors and Columbia Trust Company, a division of Columbia Bank. 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. 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 and uncertainties 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 or renewed 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; risks related to our proposed transaction with Pacific Premier (the "Transaction"), including, among others, (i) failure to complete the Transaction or unexpected delays related to the Transaction or either party's inability to satisfy closing conditions required to complete the Transaction, (ii) regulatory approvals resulting in the imposition of conditions that could adversely affect the combined company or the expected benefits of the Transaction, (iii) certain restrictions during the pendency of the Transaction that may impact the parties' ability to pursue certain business opportunities or strategic transactions, (iv) diversion of management's attention from ongoing business operations and opportunities, (v) cost savings and any revenue or expense synergies from the Transaction may not be fully realized or may take longer than anticipated to be realized, (vi) deposit attrition, customer or employee loss, and/or revenue loss as a result of the announcement of the Transaction, (viii) expenses related to the Transaction being greater than expected, and (ix) shareholder litigation that could prevent or delay the closing of the Transaction or otherwise negatively impact our business and operations; the impact of proposed or imposed tariffs by the U.S. government and retaliatory tariffs proposed or imposed by U.S. trading partners that could have an adverse impact on customers; our ability to effectively manage problem credits; the impact of bank failures or adverse developments at other banks on general investor sentiment regarding the liquidity and 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; potential adverse reactions or changes to business or employee relationships; 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.