4th Quarter 2025 Earnings Presentation January 22, 2026 Disclaimer FORWARD-LOOKING STATEMENTS This communication may contain certain forward-looking statements, including, but not limited to, certain plans, expectations, goals, projections, and statements about the benefits of the acquisition of Pacific Premier Bancorp, Inc. ("Pacific Premier") by Columbia Banking System, Inc. ("Columbia") the plans, objectives, expectations and intentions of Columbia and other statements that are not historical facts. Such ...

Core Viewpoint - Columbia Banking System (COLB) is focusing on relationship deposits, funding mix shifts, and fee growth to protect its net interest margin (NIM) as the interest rate cycle changes [1] Group 1: NIM and Financial Performance - Columbia Banking's NIM improved to 3.84% in 3Q25 from 3.56% a year ago, with expectations of NIM being "just north of" 3.90% in 4Q25 and 1Q26 [2] - The bank's deposits are granular and diversified, with a focus on full-relationship funding and proactive repricing, targeting deposit betas around 50% for rate cuts to support NIM expansion [3][9] - Columbia Banking is expected to manage down $8 billion of inherited transactional loans over approximately eight quarters starting from 3Q25, reallocating towards relationship commercial and industrial (C&I) and owner-occupied commercial real estate (CRE) [5] Group 2: Strategic Initiatives and Synergies - The merger with Pacific Premier has increased cross-selling opportunities, generating over 1,200 referrals since closing, which has contributed to deposit inflows [4][9] - Management's near-term focus includes cost normalization after systems work in 1Q26 and achieving full synergy capture by 3Q26 [1] Group 3: Market Position and Competitors - Columbia Banking currently holds a Zacks Rank 3 (Hold), indicating a balanced outlook, with key points to monitor including the 1Q26 system conversion and quarterly NIM outcomes [6] - Key peers include East West Bancorp (Zacks Rank 2) and Zions Bancorporation (Zacks Rank 2), both of which are experiencing varying impacts on their NIM due to market conditions [7][8]

Core Insights - Columbia Banking System (COLB) is shifting from transactional loans to full relationship banking following the Pacific Premier acquisition, focusing on granular deposits and fee platforms to enhance earnings durability [1][9] Loan Strategy - Management plans to reduce $8 billion in inherited transactional loans, primarily multifamily, over eight quarters starting in Q3 2025, reallocating capital to relationship-driven commercial and industrial (C&I) and owner-occupied commercial real estate (CRE) [2][9] - As of September 30, 2025, C&I and owner-occupied CRE loans represented approximately 21% and 15% of total loans, respectively, with a focus on lending that enhances leverage and returns [4] Financial Performance - The net interest margin (NIM) improved to 3.84% in Q3 2025 from 3.56% a year earlier, driven by increased customer deposits and reduced reliance on higher-cost wholesale funding [3][9] - NIM is projected to reach 3.90% in Q4 2025 and Q1 2026, supported by lower funding costs from relationship deposits [6] Revenue Growth - Fee income from treasury management and commercial card services has expanded, with non-interest income from these services making up nearly 30% as of September 30, 2025 [7] - Management anticipates a high-teens operating return on tangible common equity (ROTCE) and earnings in the low $3s for 2026, aligning with synergy realization and the loan mix shift [7][10] Relationship Development - Columbia Banking has seen improvements in C&I production and pipelines, indicating the effectiveness of its new strategy, with over 1,200 cross-sell referrals generated since the Pacific Premier deal [5] - The acquisition is expected to enhance the breadth of products offered, supporting deeper customer relationships and increasing wallet share [4]