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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities and Exchange Act of 1934

Date of Report: August 29, 2025

(Date of earliest event reported)

Columbia Banking System, Inc.

(Exact Name of Registrant as Specified in Its Charter)


Washington	000-20288	91-1422237
(State or Other Jurisdiction of Incorporation or Organization)	(Commission File Number)	(I.R.S. Employer Identification Number)

1301 A Street

Tacoma, Washington 98402-4200

(address of Principal Executive Offices)(Zip Code)

(253) 305-1900

(Registrant's Telephone Number, Including Area Code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[ ☐ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[ ☐ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[ ☐ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[ ☐ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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


TITLE OF EACH CLASS	TRADING SYMBOL	NAME OF EXCHANGE
Common Stock, No Par Value	COLB	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company [ ☐]

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act [ ]


Item 7.01			Regulation FD Disclosure

On August 29, 2025, Columbia Banking System, Inc. announced that it will conduct a quarterly earnings conference call on Thursday, October 30, 2025, at 2:00 p.m. PT (5:00 p.m. ET). During the call, management will discuss Columbia’s third quarter 2025 financial results and provide an update on recent activities. The press release announcing the conference call information is attached as Exhibit 99.1 and incorporated herein by reference.


Item 9.01			Financial Statements and Exhibits

(d)			Exhibits.
			99.1 Press Release Announcing Quarterly Earnings Conference Call
			104 Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.


			COLUMBIA BANKING SYSTEM, INC. (Registrant)
Dated: August 29, 2025			By:/s/ Kumi Yamamoto Baruffi Kumi Yamamoto Baruffi Executive Vice President, General Counsel

EX-99.1 2 colbex991q32025earningscal.htm PRESS RELEASE ANNOUNCING QUARTERLY EARNINGS CONFERENCE CALL Document

Columbia Banking System Announces Date of Third Quarter 2025 Earnings Release and Conference Call

TACOMA, Wash., Aug 29, 2025 – Columbia Banking System, Inc. (“Columbia” Nasdaq: COLB), parent company of Columbia Bank1, today announced it will release third quarter 2025 financial results on Thursday, October 30, 2025, after market close. The Company will host a conference call for investors and analysts at 2:00 p.m. PT (5:00 p.m. ET) that same day. During the call, management will discuss Columbia’s third quarter 2025 financial results and provide an update on recent activities. There will be a live question-and-answer session following the presentation. Participants may register for the call using the link below to receive dial-in details and their own unique PINs or register for the listen-only audiocast. It is recommended you join 10 minutes prior to the start time.

https://register-conf.media-server.com/register/BIde1295f868b04a969240d44867cade1a

Join the audiocast: https://edge.media-server.com/mmc/p/i6z93t5w/

Access the replay through the Company’s investor relations page under the “News & Market Data-Event Calendar” section: https://www.columbiabankingsystem.com

About Columbia

Columbia Banking System, Inc. (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 in 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 Management. Learn more at www.columbiabankingsystem.com.

Investor Relations Contact:

Jacquelynne “Jacque” Bohlen

ir@columbiabank.com

(503) 727-4100

Note Regarding Forward Looking Statements

This news release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, which can be identified by words such as "may," "expected," "anticipate," "continue," or other comparable words. In addition, all statements other than statements of historical facts that address activities that Columbia expects or anticipates will or may occur in the future are forward-looking statements. Readers are encouraged to read the SEC reports of Columbia, particularly its Annual Report on Form 10-K for the Fiscal Year ended December 31, 2024 and its Quarterly Reports on Form 10-Q for the three months ended March 31, 2025 and June 30, 2025, for meaningful cautionary language discussing why actual results may vary materially from those anticipated by management.

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1 Note: Columbia renamed Umpqua Bank to “Columbia Bank” effective July 1, 2025, and it will begin doing business under the Columbia Bank name and brand beginning on September 1, 2025.