---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-193405"
form_type: "8-K"
ticker: "COLB"
cik: "0000887343"
company_name: "COLUMBIA BANKING SYSTEM, INC."
filed_at: "2025-09-02T23:59:59+00:00"
generated_at: "2026-05-17T09:07:24.220209+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Columbia Banking System completes all-stock acquisition of Pacific Premier Bancorp

## Summary
- Each Pacific Premier share converted into 0.9150 share of Columbia common stock; former PPBI shareholders hold ~30% of combined company.
- Combined company has ~$70B assets, ~$50B loans, ~$56B deposits, and >350 branches across 8 western states.
- Three former Pacific Premier directors (Steven Gardner, M. Christian Mitchell, Jaynie Miller Studenmund) join Columbia board; Gardner also enters $2.2M consulting agreement.
- Tom Rice, former Pacific Premier CIO, joins Columbia Bank's executive leadership team as CIO.
- Systems integration expected in Q1 2026; brand transition from Umpqua to Columbia complete as of Sept 1, 2025.

## SEC filing metadata
- accession: 0001193125-25-193405
- form_type: 8-K
- ticker: COLB
- cik: 0000887343
- company_name: COLUMBIA BANKING SYSTEM, INC.
- filed_at: 2025-09-02T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 2.01, 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/887343/000119312525193405/0001193125-25-193405-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/887343/000119312525193405/d21865d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-193405
- JSON: https://secwatch.observer/filing/0001193125-25-193405.json
- Plain text: https://secwatch.observer/filing/0001193125-25-193405.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.