Columbia Banking System's Post-Merger Playbook for 2026

Margin, cost, capital and fee income set the tone for Columbia Banking System’s COLB 2026 plan following the Pacific Premier deal completion in August. The company’s Western scale, healthier margin and a clearer cost path frame the setup into 2026. 

Where Columbia Banking System Stands Now

COLB's network now spans approximately 350 branches across eight Western states after the Aug. 31, 2025, Pacific Premier acquisition, cementing statewide coverage in California and the broader West.  

As of Sept. 30, 2025, Columbia Banking System had deposits of $55.8 billion, loans and leases of $48.5 billion and total assets of $67.5 billion. This was supported by granular, relationship deposits skewed toward non-interest and money market categories.

COLB’s Margin Holds Up as Rates Drift Lower

COLB’s net interest margin (NIM) improved to 3.84% in 3Q25 from 3.56% a year earlier as deposit costs fell and wholesale funding was reduced. Management expects NIM to be roughly 3.90% in 4Q25 and 1Q26, with a temporary deposit-premium amortization boost in 4Q25 adding about $12 million to net interest income (NII) (roughly 8 bps to NIM).  

Deposit mix shift toward core customers and proactive repricing underpin Columbia Banking System’s stable core NII into early 2026, even as earning assets edge slightly lower.  Deposit mix shift away from wholesale funding and proactive repricing to defend NII.

Columbia Banking System’s Fee Income Engines Broaden

Columbia Banking System’s treasury management, commercial card and wealth/financial services and trust grew year to date, with card plus financial services and trust nearing 30% of non-interest income as of Sept. 30, 2025. 

New platforms from Pacific Premier, Custodial Trust Services, HOA banking, escrow and 1031 exchanges, plus more than 1,200 cross-sell referrals since close will continue to support deeper relationships and a more durable fee income mix.

COLB’s Cost Takeout Ramps on a Defined Timeline

Management targets $127 million in annualized cost saves from the merger, with $48 million already realized by Sept. 30, 2025.  

Operating expenses excluding CDI are expected to be in the range of $330–$340 million per quarter for several quarters. Full system conversion is planned for 1Q26, with a normalized expense run rate by 3Q26 as synergies fully materialize.  

COLB’s Capital Provides Offense and Defense

Columbia Banking System’s capital ratios improved through 2025. CET1 stood at 11.6% and total risk-based at 13.4% at 3Q25, above long-term targets. The board authorized up to $700 million in repurchases through Nov. 30, 2026, and raised the quarterly dividend by 3% to 37 cents per share.  

Tangible book dilution from the deal was 1.7%, with earn-back reduced to less than a year, leaving room to deploy excess capital while integration benefits accrue.

What Will COLB’s Success Look Like in 2026

Management reiterated a high-teens operating ROTCE framework, assuming a steady backdrop. Street earnings per share clusters in the low $3s for 2026 as cost synergies and portfolio remix flow through, with a modest step-up expected in 2027.  
 

Columbia Banking System, Inc. Price and Consensus

Columbia Banking System, Inc. price-consensus-chart | Columbia Banking System, Inc. Quote

Execution hinges on integration timing and remixing away from transactional multi-family toward relationship C&I and owner-occupied CRE, where pipelines improved in 3Q25. Overall loan growth should remain muted near term as runoff offsets originations. 

Some of the near-term risks to monitor include integration costs, FinPac loss content and competitive deposit pricing.

Integration and restructuring costs keep COLB’s near-term expenses volatile until synergy capture offsets, while higher small-ticket leasing losses at FinPac lifted charge-offs in 3Q25. The company’s office exposure was 8% of loans as of Sept. 30, 2025, with non-performing assets rising to nearly $200 million in 3Q25 from $168 million a year earlier. 
 
Competitive pricing from large banks and digital peers could pressure COLB’s deposit costs, though management is actively defending core funding and lowering reliance on wholesale sources.  

COLB’s Peer Context

East West Bancorp EWBC is a Pasadena-based commercial bank with more than 110 locations across the U.S. and Asia, often cited for cross-border and relationship banking depth in Western markets. 

Western Alliance Bancorporation WAL, headquartered in Phoenix, operates full-service business banking divisions in Arizona, California and Nevada, alongside specialized national units, offering a helpful read-through on Western deposit and C&I dynamics.

COLB’s Zacks Rank

Columbia Banking System, at present, carries a Zacks Rank of 3 (Hold), which reflects balanced near-term estimate trends while investors track integration milestones, cost saves and core margin durability into 2026. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

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