8-K/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K/A

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

February 28, 2023

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	COLB	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. ☐

Explanatory Note

On March 1, 2023, Columbia Banking System, Inc., a Washington corporation (“Columbia”), filed a Current Report on Form 8-K (the “Original Report”) to report that, effective as of February 28, 2023, after the close of business, Columbia completed its merger with Umpqua Holdings Corporation, an Oregon corporation (“Umpqua”), pursuant to the Agreement and Plan of Merger, dated October 11, 2021, as amended by Amendment No. 1 to the Merger Agreement, dated as of January 9, 2023, (as amended, the “Merger Agreement”) by and among Umpqua, Columbia, and Cascade Merger Sub, Inc., a Delaware corporation and a direct, wholly-owned subsidiary of Columbia (“Merger Sub”). Pursuant to the Merger Agreement, (i) Merger Sub merged with and into Umpqua (the “Merger”), with Umpqua as the surviving entity, and (ii) immediately thereafter, Umpqua merged with and into Columbia, with Columbia as the surviving entity (the “Subsequent Merger” and, together with the Merger, the “Mergers”). Promptly following the closing of the Subsequent Merger, Columbia State Bank, a Washington state-chartered commercial bank and a wholly-owned subsidiary of Columbia, merged with and into Umpqua Bank, an Oregon state-chartered commercial bank and, by virtue of the Mergers, a wholly-owned subsidiary of Columbia (the “Bank Merger”), with Umpqua Bank surviving the Bank Merger.

This amendment to the Original Report (the “Amendment”) is being filed to provide the financial statements and pro forma financial information required by Item 9.01 of Form 8-K.

The pro forma financial information included in this Amendment has been presented for informational purposes only, as required by Form 8-K. It does not purport to represent the actual results of operations that Columbia and Umpqua would have achieved had the companies been combined during the periods presented in the pro forma financial information and is not intended to project the future results of operations that the combined company may achieve after completion of the Mergers. The pro forma financial information combines the historical consolidated financial position and results of operations of Columbia and Umpqua as a reverse acquisition of Columbia by Umpqua. Columbia has posted to its website a supplemental presentation intended to provide additional information on the accounting treatment of a reverse acquisition.

Except as described in this Amendment, all other information in the Original Report remains unchanged.

Item 9.01. Financial Statements and Exhibits.

(a) Financial statements of businesses or funds acquired.

The financial statements of Umpqua required by Item 9.01(a) of Form 8-K are attached hereto as Exhibit 99.1 and incorporated by reference into this Item 9.01(a).

(b) Pro forma financial information.

The pro forma financial information required by Item 9.01(b) of Form 8-K and the unaudited pro forma capital ratios of Columbia and Umpqua Bank are attached hereto as Exhibit 99.2 and incorporated herein by reference into this Item 9.01(b).

(d) Exhibits.

The following exhibits are filed as part of this Current Report:

Exhibit No.	Description
23.1	Consent of Deloitte & Touche LLP, Independent Registered Public Accounting Firm for Umpqua Holdings Corporation.
99.1	Audited consolidated balance sheets of Umpqua Holdings Corporation as of December 31, 2022 and December 31, 2021, the related consolidated statements of operations, comprehensive income, changes in shareholders’ equity and cash flows of Umpqua Holdings Corporation for each of the three years in the period ended December 31, 2022, and the notes related thereto (incorporated by reference to Part II, Item 8 of Umpqua Holdings Corporation’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on February 24, 2023 (File No. 001-34624)).
99.2	Unaudited pro forma condensed combined balance sheet as of December 31, 2022, the unaudited pro forma condensed combined statement of income for the fiscal year ended December 31, 2022, the notes related thereto and the unaudited pro forma capital ratios of Columbia and Umpqua Bank.
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.

Date: March 3, 2023	COLUMBIA BANKING SYSTEM, INC.
	/s/ Kumi Yamamoto Baruffi
	Name: Kumi Yamamoto Baruffi
	Title:   General Counsel

EX-23.1

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in Registration Statement Nos. 333-160371, 333-225955, and 333-270191 on Form S-8 and Registration Statement No. 333-261936 on Form S-3 of Columbia Banking System, Inc. of our report dated February 24, 2023, relating to the financial statements of Umpqua Holdings Corporation and the effectiveness of Umpqua Holdings Corporation’s internal control over financial reporting incorporated by reference in this Current Report on Form 8-K/A dated March 3, 2023.

/s/ Deloitte & Touche LLP

Portland, Oregon

March 3, 2023

EX-99.2

Exhibit 99.2

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

The following unaudited pro forma condensed combined financial information combines the historical consolidated financial position and results of operations of Columbia Banking System, Inc. (“Columbia”) and Umpqua Holdings Corporation (“Umpqua”) as a reverse acquisition of Columbia by Umpqua. The merger of Columbia and Umpqua (the “merger”) closed after close of business on February 28, 2023 and provided that each share of common stock of Umpqua issued and outstanding immediately prior to the effective time of the merger was automatically converted into the right to receive 0.5958 of a share (the “exchange ratio” and such shares, the “merger consideration”) of common stock of Columbia. The following unaudited pro forma condensed combined financial information and the accompanying notes (the “unaudited pro forma financial information”) are presented to illustrate the estimated effects of the following:

• the reverse acquisition of Columbia by Umpqua pursuant to the Agreement and Plan of Merger, dated as of October 11, 2021, as amended on January 9, 2023, by and among Umpqua, Columbia and Cascade Merger Sub, Inc. (the “reverse acquisition”);

• a $20 million contribution by Columbia and Umpqua to the charitable foundation of the combined company following the closing of the reverse acquisition (the “donations”); and

• the divestiture of certain Columbia branches, including loans, premises and equipment, and deposits (the “divestitures”) prior to the closing of the reverse acquisition.

The accompanying unaudited pro forma condensed combined balance sheet as of December 31, 2022, combines the historical consolidated balance sheets of Columbia and Umpqua as of such date and includes adjustments that depict the accounting for the reverse acquisition, donation, and divestitures (as defined herein) as required by GAAP (“pro forma balance sheet transaction accounting adjustments”) as of February 28, 2023. Also, the unaudited pro forma condensed combined statements of income for the year ended December 31, 2022, combine the historical consolidated statements of income of Columbia and Umpqua for the same period and include adjustments that depict the effects of the pro forma balance sheet transaction accounting adjustments assuming those adjustments were made as of January 1, 2022 (“pro forma income statement transaction accounting adjustments”). We refer to pro forma balance sheet transaction accounting adjustments and pro forma income statement transaction accounting adjustments collectively as the “transaction accounting adjustments.”

The unaudited pro forma financial information is based on and should be read in conjunction with the separate historical financial statements and notes thereto in each of Columbia’s and Umpqua’s SEC filings including:

• the historical audited consolidated financial statements of Columbia and accompanying notes included in Columbia’s Annual Report on Form 10-K for the year ended December 31, 2022; and

• the historical audited consolidated financial statements of Umpqua and accompanying notes included in Umpqua’s Annual Report on Form 10-K for the year ended December 31, 2022.

The unaudited pro forma financial information is provided for illustrative information purposes only. The unaudited pro forma financial information is not necessarily, and should not be assumed to be, an indication of the actual results that would have been achieved had the reverse acquisition, donations, and the divestitures been completed as of the dates indicated or that may be achieved in the future. The unaudited pro forma financial information has been prepared in accordance with Regulation S-X Article 11, Pro Forma Financial.

The unaudited pro forma financial information also does not consider any potential effects of changes in market conditions on revenues, expense efficiencies, asset dispositions (other than the divestitures), and share repurchases, among other factors. In addition, as explained in more detail in the accompanying notes, the preliminary allocation of the pro forma purchase price reflected in the unaudited pro forma financial information is subject to adjustment and may vary significantly from the final purchase price allocation.

The Company has not completed the valuation analysis and calculations in sufficient detail necessary to arrive at the required estimates of the fair market value of the Columbia assets to be acquired or liabilities to be assumed, other than a preliminary estimate for intangible assets and certain financial assets and financial liabilities. Accordingly, apart from the aforementioned estimates, certain Columbia assets and liabilities are presented at their respective carrying amounts and should be treated as preliminary values.

1

A final determination of the fair value of Columbia’s assets and liabilities will be based on Columbia’s actual assets and liabilities as of February 28, 2023. Any changes in the fair values of the net assets or total purchase consideration as compared with the information shown in the unaudited pro forma financial information may change the amount of the total purchase consideration allocated to goodwill and other assets and liabilities and may impact the combined company’s statement of income. The final purchase consideration allocation may be materially different than the preliminary purchase consideration allocation presented in the unaudited pro forma financial information.

Certain reclassifications to conform historical financial statement presentations of Columbia to Umpqua have been made in the unaudited pro forma financial information. The transaction accounting adjustments have been made solely for the purpose of providing the unaudited pro forma financial information.

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UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET

The unaudited pro forma condensed combined balance sheet as of December 31, 2022, is presented as if the reverse acquisition had occurred on December 31, 2022.

	December 31, 2022
(dollars in thousands)	Umpqua Historical			Columbia Historical			Transaction Accounting Adjustments			Notes		Pro Forma Combined
ASSETS
Cash and due from banks	$	327,313		$	267,575		$	(2,774	)			$	592,114
Interest bearing cash and temporary investments		967,330			29,103			(92,444	)				903,989
Total cash and cash equivalents		1,294,643			296,678			(95,218	)		A		1,496,103
Investment securities
Equity and other, at fair value		72,959			1,269			—					74,228
Available for sale, at fair value		3,196,166			4,598,804			—					7,794,970
Held to maturity, at amortized cost		2,476			2,034,792			(312,014	)		B		1,725,254
Loans held for sale, at fair value		71,647			76,843			(69,683	)		C		78,807
Loans and leases		26,155,981			11,603,173			(716,663	)		D		37,042,491
Allowance for credit losses on loans and leases		(301,135	)		(158,438	)		—			E		(459,573	)
Net loans and leases		25,854,846			11,444,735			(716,663	)				36,582,918
Restricted equity securities		47,144			48,410			—					95,554
Premises and equipment, net		176,016			160,578			42,018			F		378,612
Goodwill		—			823,172			179,463			G		1,002,635
Other intangible assets, net		4,745			25,949			766,362			H		797,056
Other assets		1,127,997			760,707			81,204			I		1,969,908
Total assets	$	31,848,639		$	20,271,937		$	(124,531	)			$	51,996,045
LIABILITIES AND SHAREHOLDERS’ EQUITY
Deposits
Non-interest bearing	$	10,288,849		$	8,330,912		$	(238,635	)			$	18,381,126
Interest bearing		16,776,763			8,341,161			(313,910	)				24,804,014
Total deposits		27,065,612			16,672,073			(552,545	)		J		43,185,140
Securities sold under agreements to repurchase		308,769			95,168			—					403,937
Borrowings		906,175			954,315			437,795			K		2,298,285
Junior subordinated debentures, at fair value		323,639			—			—					323,639
Junior and other subordinated debentures, at amortized cost		87,813			20,310			(378	)		L		107,745
Other liabilities		676,805			316,918			—					993,723
Total liabilities		29,368,813			18,058,784			(115,128	)				47,312,469
SHAREHOLDERS’ EQUITY
Preferred stock		—			—			—					—
Common stock		3,450,493			1,944,471			393,322			M		5,788,286
Treasury stock		—			(70,834	)		70,834			N		—
(Accumulated deficit) retained earnings		(543,803	)		850,011			(984,054	)		O		(677,846	)
Accumulated other comprehensive (loss) income		(426,864	)		(510,495	)		510,495			P		(426,864	)
Total shareholders’ equity		2,479,826			2,213,153			(9,403	)				4,683,576
Total liabilities and shareholders’ equity	$	31,848,639		$	20,271,937		$	(124,531	)			$	51,996,045

See accompanying notes to the unaudited pro forma condensed combined financial statements.

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UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF INCOME

The unaudited pro forma condensed combined income statements for the year ended December 31, 2022, are presented as if the reverse acquisition had occurred on January 1, 2022.

	Year Ended December 31, 2022
(in thousands, except per share amounts)	Umpqua Historical			Columbia Historical		Transaction Accounting Adjustments			Notes		Pro Forma Combined
INTEREST INCOME
Interest and fees on loans and leases	$	1,050,258		$	502,159	$	215,248			Q	$	1,767,665
Interest and dividends on investment securities		78,053			147,899		190,346			R		416,298
Interest on temporary investments and interest bearing deposits		19,706			2,748		—					22,454
Total interest income		1,148,017			652,806		405,594					2,206,417
INTEREST EXPENSE
Interest on deposits		48,195			16,497		10,794			S		75,486
Interest on securities sold under agreement to repurchase and federal funds purchased		997			923		—					1,920
Interest on borrowings		8,920			5,382		17			T		14,319
Interest on junior and other subordinated debentures		19,889			807		75			U		20,771
Total interest expense		78,001			23,609		10,886					112,496
Net interest income		1,070,016			629,197		394,708					2,093,921
PROVISION FOR CREDIT LOSSES		84,016			1,450		124,503			V		209,969
Net interest income after provision for credit losses		986,000			627,747		270,205					1,883,952
NON-INTEREST INCOME
Service charges on deposits		48,365			28,754		(1,135	)		W		75,984
Card-based fees		37,370			20,186		(268	)		X		57,288
Financial services and trust revenue		90			17,659		—					17,749
Residential mortgage banking revenue, net		106,859			3,289		—					110,148
(Loss) gain on investment securities, net		(7,097	)		30		—					(7,067	)
Other income		13,941			20,566		(86	)		Y		34,421
Total non-interest income		199,528			90,484		(1,489	)				288,523
NON-INTEREST EXPENSE
Salaries and employee benefits		441,226			243,314		(3,453	)		Z		681,087
Occupancy and equipment, net		138,451			76,340		1,145			AA		215,936
Intangible amortization		4,095			8,698		141,252			AB		154,045
Other expenses		151,178			72,232		19,642			AC		243,052
Total non-interest expense		734,950			400,584		158,586					1,294,120
Income before provision for income taxes		450,578			317,647		110,130					878,355
Provision for income taxes		113,826			67,469		29,184			AD		210,479
Net income	$	336,752		$	250,178	$	80,946				$	667,876
Earnings per common share:
Basic	$	1.55		$	3.20						$	3.21
Diluted	$	1.55		$	3.20						$	3.21
Weighted average number of common shares outstanding:
Basic		216,980			78,047		(86,929	)		AE		208,098
Diluted		217,403			78,193		(87,352	)		AF		208,244

See accompanying notes to the unaudited pro forma condensed combined financial statements.

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NOTES TO THE UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

Note 1—Basis of Presentation

The accompanying unaudited pro forma financial information has been prepared in accordance with Article 11 of Regulation S-X to illustrate the effects of the reverse acquisition, the donations, and the divestitures. The unaudited pro forma condensed combined income statement for the year ended December 31, 2022 combine the historical consolidated income statement of Columbia and Umpqua, giving effect to the reverse acquisition as if it had been completed on January 1, 2022. The accompanying unaudited pro forma condensed combined balance sheet as of December 31, 2022 combines the historical consolidated balance sheets of Columbia and Umpqua, giving effect to the reverse acquisition as if it had been completed on December 31, 2022.

Columbia estimated common equity tier 1 capital ratio was 8.7% and the estimated total capital ratio was 10.9%, the estimated total capital ratio for Umpqua Bank was 10.3%, based on the pro forma financials as of December 31, 2022 (without giving effect to the divestitures). Please see “Unaudited Pro Forma Capital Ratios” of this Exhibit 99.2.

The reverse acquisition will be accounted for under the reverse acquisition method of accounting with Umpqua treated as the accounting acquirer. Under the reverse acquisition method of accounting, the assets and liabilities of Columbia, as of the closing date, will be recorded by Umpqua at their respective fair values and the excess of the merger consideration over the fair value of Columbia’s net assets will be recognized as goodwill.

The donations will be accounted for as an other expense immediately following close of the reverse acquisition.

The divestiture of certain Columbia branches, including loans, premises and equipment, and deposits (the “divestitures”), in satisfaction of commitments to the Antitrust Division of the Department of Justice (the “DOJ”) and the Board of Governors of the Federal Reserve System (the “Federal Reserve”), are also reflected in the unaudited pro forma financial information.

Columbia has not identified all adjustments necessary to conform Columbia’s accounting policies to Umpqua’s accounting policies. Although the merger has closed, Columbia is in the process of performing a more detailed review. As a result of that review, differences could be identified between the accounting policies of the two companies that, when conformed, could have a material impact on the combined company’s financial information.

Note 2—Preliminary Purchase Accounting Allocation

The transaction accounting adjustments depict the completion of the merger, including the allocation of the preliminary purchase price. The impact of equity awards on the purchase price is immaterial and has been excluded in the unaudited pro forma financial information. The excess of the purchase price over the fair value of net assets acquired is recorded as goodwill. The transaction accounting adjustments included in the pro forma financial statements are based upon available information and certain assumptions considered reasonable, and may be revised as additional information becomes available.

The unaudited pro forma condensed combined balance sheet has been adjusted to reflect the preliminary calculation of the estimated purchase price to identifiable net assets acquired. Since the acquisition will be accounted for as a reverse acquisition, the estimated purchase price was determined in accordance with FASB ASC 805-40-30-2, which explains that the purchase price in a reverse acquisition is determined based on “the number of equity interests the legal acquiree would have had to issue to give the owners of the legal acquirer the same percentage equity interest in the combined entity that results from the reverse acquisition.”

5

The first step in estimating the purchase price in the merger is to determine the pro forma ownership of the combined company following the merger. The table below summarizes, for each current shareholder group, the pro forma ownership of Columbia common stock following the merger as well as the pro forma market capitalization of the combined company using shares of Columbia common stock and Umpqua common stock outstanding at December 31, 2022 and the closing price of Columbia common stock on February 28, 2023.

	Columbia Ownership and Market Value Table (Pro Forma)
(in thousands)	Number of Umpqua Outstanding Shares		Percentage Ownership			Market Value at $29.73 Columbia Share Price
Current Columbia shareholders		78,871		37.8	%	$	2,344,826
Current Umpqua shareholders		130,051		62.2	%		3,866,405
Total		208,922		100.0	%	$	6,211,231

Next, the hypothetical number of shares of Umpqua common stock that would have to be issued to give Columbia shareholders the same percentage ownership in the combined company is calculated in the table below (based on shares of Umpqua common stock outstanding at December 31, 2022):

	Hypothetical Umpqua Ownership
(in thousands)	Number of Umpqua Outstanding Shares		Percentage Ownership
Current Columbia shareholders		132,378		37.8	%
Current Umpqua shareholders		218,279		62.2	%
Total		350,657		100.0	%

Finally, the purchase price for purposes of the transaction accounting adjustments is calculated based on the number of hypothetical shares of Umpqua common stock to be issued to Columbia shareholders, multiplied by the share price as demonstrated in the table below (amounts in thousands except per share data):

Number of hypothetical Umpqua common shares issued to Columbia shareholders		132,378
Umpqua market price per share as of February 28, 2023	$	17.66
Purchase price determination of hypothetical Umpqua shares issued to Columbia shareholders	$	2,337,793

The final purchase price paid by Columbia in shares of Columbia common stock upon the completion of the reverse acquisition were determined based on the closing price of Columbia common stock on the closing date and the number of issued and outstanding shares of Umpqua common stock immediately prior to the effective time. Actual adjustments may differ from the amounts reflected in the unaudited pro forma financial information, and the differences may be material.

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The following table shows the allocation of the preliminary purchase price:

(in thousands)	December 31, 2022
Fair value consideration paid to Umpqua common shareholders
Cash paid			$	—
Fair value of common shares issued and exchanged				2,337,793
Total pro forma purchase price			$	2,337,793
Fair value of assets acquired:
Cash and due from banks	$	296,678
Equity and other		1,269
Available for sale		4,598,804
Held to maturity		1,722,778
Loans held for sale		76,843
Loans and leases		10,852,575
Restricted equity securities		48,410
Premises and equipment		212,252
Other intangible assets		792,311
Other assets		780,473
Total assets acquired	$	19,382,393
Fair value of liabilities assumed:
Deposits	$	16,661,070
Securities sold under agreements to repurchase		95,168
Borrowings		954,147
Junior and other subordinated debentures		19,932
Other liabilities		316,918
Total liabilities assumed	$	18,047,235
Net assets acquired			$	1,335,158
Preliminary pro forma goodwill			$	1,002,635

Columbia estimated the fair value of certain Columbia assets and liabilities based on a preliminary valuation analysis, due diligence information, information presented in Columbia’s SEC filings and other publicly available information. As of the date of this Current Report on Form 8-K, Columbia has not completed the valuation analysis and calculations in sufficient detail necessary to arrive at the required estimates of the fair value of Columbia’s assets acquired or liabilities assumed for reverse acquisition accounting purposes, other than a preliminary estimate for intangible assets and certain financial assets and financial liabilities. Accordingly, apart from the aforementioned, certain Columbia assets and liabilities are presented at their respective carrying amounts and should be treated as preliminary fair values. A final determination of the fair value of Columbia’s assets and liabilities will be based on Columbia’s actual assets and liabilities as of the effective time. Actual adjustments may differ from the amounts reflected in the unaudited pro forma financial information, and the differences may be material.

A final determination of the fair value of Columbia’s assets acquired and liabilities assumed will be performed. Any changes in the fair values of the net assets or total purchase price as compared with the information shown in the unaudited pro forma financial information may change the amount of the total purchase price allocated to goodwill and other assets and liabilities and may impact the combined company’s statement of income. The final purchase price allocation may be materially different than the preliminary purchase price allocation presented in the unaudited pro forma financial information.

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Note 3—Transaction Accounting Adjustments

The following transaction accounting adjustments have been reflected in the unaudited pro forma financial information. All adjustments are based on current assumptions and valuations, which are subject to change.

Balance Sheet

(dollars in thousands)		December 31, 2022
A	Adjustments to cash and cash equivalents
	To reflect cash paid for merger expenses.	$	(72,444	)
	To reflect cash paid for donations.		(20,000	)
	To reflect cash in divested branches.		(2,774	)
		$	(95,218	)
	Remaining merger expenses expected to be incurred for change in control agreements, investment banker fees, legal fees, and other accounting and audit related costs, that are directly attributable to the merger, are reflected in the pro forma combined condensed statement of financial condition. Other expenses are expected to be incurred in the merger for termination of leases, signage and store conversions, vendor contracts, severance, and retention, as well as other miscellaneous costs. It is estimated that these amounts not yet incurred will be an additional $100 million, but are not reflected in the pro formas herein.
B	Adjustment to investment securities, held to maturity
	To reflect estimated fair value of acquired investment securities.	$	(312,014	)
C	Adjustment to loans held for sale
	To reflect loans sold with divestiture of Columbia branches.	$	(69,683	)
D	Adjustments to loans and leases
	To reflect estimated fair value related to current interest rates and liquidity on acquired loans and leases. This adjustment will be recognized into income using the effective interest method over the remaining life of the loans and leases.
	Fair values were estimated for portfolios of loans with similar behavioral characteristics. Loans were segregated by type, including commercial real estate, commercial business, agriculture, construction, one-to-four family residential real estate, and other consumer. Each loan type was further segregated by performance characteristics to bifurcate PCD from non-PCD loans. The fair value of loans by type and by performance characteristics (each a loan pool) was calculated using a discounted cash flow methodology over the weighted average life of each pool. The discount rate was determined using a weighted approach on both a market approach as well as a recent origination discount approach. The market approach was based on spreads ranging between 1.9% and 4.0%, observed on publicly available market rates of loans that were comparable to the loans in the subject pools. The recent origination discount approach was based on new loan rate spreads ranging between approximately 1.4% and 3.7% based on Columbia originated loans in the three months prior to valuation. The weight applied to each approach was based on the comparability of loan pool risk characteristics and availability of recent origination and public market data. A liquidity premium of approximately 0.4% to 0.5% for non-PCD loans was then applied based on spreads between yields of USD AA Financial corporate bonds and US Treasury Strip rates for each pool’s respective weighted average life. An additional spread of 1.5% was applied to PCD loans based on market data. The discount spreads post-liquidity premium were applied over the three-month LIBOR swap rate to discount the loan level cash flows for each respective loan pool. These amounts were discounted further by embedded probable losses expected to be realized in each loan pool, which were based on current expected credit loss estimates. Resulting weighted average loan rate fair value discount was 5.1%.	$	(592,160	)
	To reflect estimated lifetime credit losses on acquired loans and leases.		(158,438	)
	Net fair value pro forma adjustments.		(750,598	)
	Gross up of purchase credit deteriorated (“PCD”) loans and leases for credit mark - See E below for Allowance.		33,935
		$	(716,663	)

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Balance Sheet

(dollars in thousands)	December 31, 2022
E   Adjustments to allowance for credit losses on loans and leases
To eliminate Columbia allowance at merger date as the credit risk is contemplated in the fair value adjustments.	$	158,438
To reflect estimated lifetime credit losses on acquired PCD loans and leases.		(33,935	)
To reflect estimated lifetime credit losses on acquired non-PCD loans and leases.		(124,503	)
	$	—
Estimates of credit losses were based on Columbia’s historical allowance for credit losses on loans and leases, with PCD and non-PCD loan and lease classification based on performance metrics of acquired loans and leases.
F   Adjustment to premises and equipment, net
To record the estimated fair value of acquired premises and equipment.	$	51,674
To reflect divestiture of Columbia branches.		(9,656	)
	$	42,018
G  Adjustments to goodwill
To eliminate Columbia goodwill at merger date.	$	(823,172	)
To record the goodwill associated with the merger.		1,002,635
	$	179,463
H  Adjustments to other intangible assets, net
To eliminate Columbia other intangible assets, net.	$	(25,949	)
To record the estimated fair value of acquired identifiable intangible assets, calculated as 5.49% of Columbia core deposits based on a November 30, 2022 valuation. The acquired core deposit intangible will be amortized over ten years using a sum-of-the-years-digits method.		792,311
	$	766,362
I   Adjustment to other assets
To reflect deferred tax liability created in the Acquisition, which is calculated as follows:
Adjustment to investment securities, held to maturity	$	312,014
Adjustments to loans and leases, net		592,160
Adjustment to premises and equipment, net		(51,674	)
Adjustments to other intangible assets, net		(766,362	)
Adjustment to deposits		(11,003	)
Adjustment to borrowings		(168	)
Adjustment to junior and other subordinated debentures, at amortized cost		(378	)
Subtotal for fair value adjustments	$	74,589
Calculated deferred tax asset at estimated combined statutory federal and state rate of 26.5%	$	19,766
To record deferred tax asset created on provision for credit losses on Columbia’s non-PCD loans.		32,993
To reflect reduction in taxes payable due to deductible portion of merger expenses.		23,718
To reflect reduction in taxes payable due to donations.		5,300
To reflect other assets sold with divestiture of Columbia branches.		(573	)
	$	81,204

9

Balance Sheet

(dollars in thousands)	December 31, 2022
J   Adjustment to deposits
To reflect estimated fair value at merger date based on current market rates for similar products. This adjustment will be amortized into income over the estimated lives of the deposits, which is approximately eight months.	$	(11,003	)
To reflect deposits sold with divestiture of Columbia branches.
Non-interest bearing demand deposits		(238,635	)
Interest bearing deposits		(302,907	)
	$	(552,545	)
K  Adjustment to borrowings
To reflect estimated fair value at merger date based on current market rates and spreads for similar borrowings. This estimated discount will be amortized to interest expense over the remaining contractual life of such borrowings, which is approximately ten years.	$	(168	)
To reflect borrowings to fund divestiture of branches.		437,963
	$	437,795
L   Adjustment to junior and other subordinated debentures, at amortized cost
To reflect estimated fair value at reverse acquisition date based on current market rates and spreads for similar subordinated debentures. This estimated premium will be accreted to interest expense over the remaining contractual life of such borrowings, which is approximately five years.	$	(378	)
M Adjustments to common stock
To eliminate historical Columbia common stock.	$	(1,944,471	)
To reflect the acquisition-date fair value of the consideration transferred by Umpqua for its interest in Columbia.		2,337,793
	$	393,322
N  Adjustment to treasury stock
To eliminate historical Columbia treasury stock.	$	70,834
O  Adjustments to accumulated deficit/retained earnings
To eliminate historical Columbia retained earnings.	$	(850,011	)
To adjust for estimated lifetime credit losses on acquired non-PCD loans and leases on an after tax basis.		(91,510	)
To adjust for after tax merger expenses.		(48,726	)
To adjust for gain on sale of branch divestitures.		20,893
To adjust for after tax donations.		(14,700	)
	$	(984,054	)
P   Adjustment to accumulated other comprehensive income
To eliminate historical Columbia accumulated other comprehensive income.	$	510,495

10

Income Statement

(dollars in thousands, except per share amounts)	Year Ended December 31, 2022
Q  Adjustment to interest and fees on loans and leases
To reflect accretion of loan rate premium and non-PCD credit discount resulting from loans and leases fair value Adjustment D using sum-of-years-digits method to approximate effective yield method over the estimated lives of the acquired loan portfolio, which is approximately six years.	$	217,617
To reflect interest and fees on loans and leases on Columbia branch divestitures.		(2,369	)
	$	215,248
R  Adjustment to interest and dividends on investment securities
To reflect estimated accretion of the discount on acquired held-to-maturity securities fair value Adjustment B using sum of years digits method to approximate effective yield method over the estimated lives of the acquired held-to-maturity portfolio, which is approximately ten years.	$	190,346
S   Adjustment to interest on deposits
To reflect amortization of deposit discount resulting from deposit fair value pro forma Adjustment J based on weighted average life of time deposits being approximately eight months.	$	11,003
To reflect interest on deposits on Columbia branch divestitures.		(209	)
	$	10,794
T   Adjustment to interest on borrowings
To reflect accretion of borrowing premium resulting from borrowing fair value pro forma Adjustment K based on the remaining life of borrowings of approximately ten years.	$	17
U  Adjustment to interest on junior and other subordinated debentures
To reflect accretion of subordinated debenture premium resulting from subordinated debenture fair value pro forma Adjustment L based on the life of subordinated debenture of approximately five years.	$	75
V  Adjustment to provision for credit losses
To record provision for credit losses on Columbia’s non-PCD loans.	$	124,503
W   Adjustment to service charges on deposits
To reflect service charges on deposits on Columbia branch divestitures.	$	(1,135	)
X  Adjustment to card based fees
To reflect other income on Columbia branch divestitures.	$	(268	)
Y  Adjustment to other income
To reflect other income on Columbia branch divestitures.	$	(86	)
Z   Adjustment to salaries and employee benefits
To reflect salaries and employee benefits on Columbia branch divestitures.	$	(3,453	)

11

Income Statement

(dollars in thousands, except per share amounts)		Year Ended December 31, 2022
AA	Adjustment to occupancy and equipment, net
	To reflect straight line amortization of premises and equipment purchase accounting adjustment resulting from premises and equipment pro forma Adjustment F based on 20 year expected life.	$	2,584
	To reflect occupancy and equipment on Columbia branch divestitures.		(1,439	)
		$	1,145
AB	Adjustments to intangible amortization
	To remove Columbia intangible assets amortization.	$	(8,698	)
	To reflect amortization of acquired intangible assets fair value pro forma Adjustment H based on amortization period of 10 years and using the sum-of-the-years-digits method of amortization.		149,950
		$	141,252
AC	Adjustment to other expenses
	To reflect the contribution to the charitable foundation, which occurred immediately following the close of the Acquisition.	$	20,000
	To reflect other expenses on Columbia branch divestitures.		(358	)
		$	19,642
AD	Adjustment to income tax provision
	To reflect the income tax effect of transaction accounting adjustments at the estimated combined statutory federal and state rate of 26.5%.	$	29,184
AE	Adjustments to weighted average number of common shares outstanding - Basic
	To reflect acquisition of Umpqua common shares.		(216,980	)
	To reflect issuance of Columbia common stock as Umpqua shareholders will receive 0.5958 of a share of Columbia common stock for each share of Umpqua common stock they hold immediately prior to the merger.		130,051
			(86,929	)
AF	Adjustments to weighted average number of common shares outstanding - Diluted
	To reflect acquisition of Umpqua common shares.		(217,403	)
	To reflect issuance of Columbia common stock as Umpqua shareholders will receive 0.5958 of a share of Columbia common stock for each share of Umpqua common stock they hold immediately prior to the merger.		130,051
			(87,352	)

Note 4—Divestitures in Connection with the Reverse Acquisition

In connection with the merger, Columbia sold seven branches in Washington and Oregon to 1st Security Bank of Washington, the wholly-owned subsidiary of FS Bancorp, Inc., and three branches in Northern California to First Northern Bank of Dixon, the wholly-owned subsidiary of First Northern Community Bancorp. The branches, with approximately $542 million in total deposits and $70 million in total loans, were divested in satisfaction of commitments to the Antitrust Division of the DOJ and the Federal Reserve in connection with the reverse acquisition. The divestitures occurred in the first quarter of 2023. As such, these divestitures are included in the unaudited pro forma financial information.

12

UNAUDITED PRO FORMA CAPITAL RATIOS

The following presents the regulatory capital ratios of each of Columbia Banking System, Inc. (“Columbia”) and Umpqua Bank giving effect to the merger of Columbia and Umpqua Holdings Corporation (“Umpqua”) as a reverse acquisition of Columbia by Umpqua. The following unaudited pro forma capital ratios do not give effect to the divestiture of certain Columbia branches, including loans, premises, equipment and deposits prior to the closing of the reverse acquisition.

	As of December 31, 2022
Columbia Banking System, Inc.
Common equity tier 1 capital ratio		8.7	%
Tier 1 capital ratio		8.7	%
Total capital ratio		10.9	%
Leverage ratio		6.8	%
Umpqua Bank
Common equity tier 1 capital ratio		9.3	%
Tier 1 capital ratio		9.3	%
Total capital ratio		10.3	%
Leverage ratio		7.4	%

13

XML

Document and Entity Information	Feb. 28, 2023
Cover [Abstract]
Document Type	8-K/A
Amendment Flag	true
Document Period End Date	Feb. 28, 2023
Entity Registrant Name	Columbia Banking System, Inc.
Entity Incorporation, State or Country Code	WA
Entity File Number	000-20288
Entity Tax Identification Number	91-1422237
Entity Address, Address Line One	1301 A Street
Entity Address, City or Town	Tacoma
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98402-4200
City Area Code	253
Local Phone Number	305-1900
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Title of 12(b) Security	Common Stock
Trading Symbol	COLB
Security Exchange Name	NASDAQ
Entity Emerging Growth Company	false
Amendment Description	On March 1, 2023, Columbia Banking System, Inc., a Washington corporation (“Columbia”), filed a Current Report on Form 8-K (the “Original Report”) to report that, effective as of February 28, 2023, after the close of business, Columbia completed its merger with Umpqua Holdings Corporation, an Oregon corporation (“Umpqua”), pursuant to the Agreement and Plan of Merger, dated October 11, 2021, as amended by Amendment No. 1 to the Merger Agreement, dated as of January 9, 2023, (as amended, the “Merger Agreement”) by and among Umpqua, Columbia, and Cascade Merger Sub, Inc., a Delaware corporation and a direct, wholly-owned subsidiary of Columbia (“Merger Sub”). Pursuant to the Merger Agreement, (i) Merger Sub merged with and into Umpqua (the “Merger”), with Umpqua as the surviving entity, and (ii) immediately thereafter, Umpqua merged with and into Columbia, with Columbia as the surviving entity (the “Subsequent Merger” and, together with the Merger, the “Mergers”). Promptly following the closing of the Subsequent Merger, Columbia State Bank, a Washington state-chartered commercial bank and a wholly-owned subsidiary of Columbia, merged with and into Umpqua Bank, an Oregon state-chartered commercial bank and, by virtue of the Mergers, a wholly-owned subsidiary of Columbia (the “Bank Merger”), with Umpqua Bank surviving the Bank Merger.This amendment to the Original Report (the “Amendment”) is being filed to provide the financial statements and pro forma financial information required by Item 9.01 of Form 8-K.The pro forma financial information included in this Amendment has been presented for informational purposes only, as required by Form 8-K. It does not purport to represent the actual results of operations that Columbia and Umpqua would have achieved had the companies been combined during the periods presented in the pro forma financial information and is not intended to project the future results of operations that the combined company may achieve after completion of the Mergers. The pro forma financial information combines the historical consolidated financial position and results of operations of Columbia and Umpqua as a reverse acquisition of Columbia by Umpqua. Columbia has posted to its website a supplemental presentation intended to provide additional information on the accounting treatment of a reverse acquisition.Except as described in this Amendment, all other information in the Original Report remains unchanged.
Entity Central Index Key	0000887343