Exhibit 99.1

Byline Bancorp, Inc. Reports Third Quarter 2023 Financial Results

Net income of $28.2 million, $0.65 diluted earnings per share

Chicago, IL, October 26, 2023 – Byline Bancorp, Inc. (NYSE: BY), today reported:

			For the quarter					Third Quarter Highlights
		3Q23		2Q23		3Q222
Financial Results (in thousands)								(compared to 2Q23)
	Net interest income	$	92,452	$	76,166	$	68,635	Completed the acquisition and integration of Inland Bancorp, Inc.
	Non-interest income		12,376		14,291		12,043
	Total Revenue1		104,828		90,457		80,678
	Noninterest expense		57,891		49,328		46,041	Top Illinois SBA 7(a) lender for 15th consecutive year
	Pre-tax pre-provision net income (PTPP)1		46,937		41,129		34,637
	Provision for credit losses		8,803		5,790		7,208
	Provision for income taxes		9,912		9,232		7,020	Income Statement
	Net Income	$	28,222	$	26,107	$	20,409	• NIM expanded 14 bps
Per Share								• Adjusted net income1 of $33.3 million, or
	Diluted EPS	$	0.65	$	0.70	$	0.55	$0.77 per adjusted diluted share1
	Dividends declared per common share		0.09		0.09		0.09
	Book value		21.04		21.58		19.64	• PTPP1 of $46.9 million, increase of 14.1%
	Tangible book value per share1		16.35		17.43		15.36
								• Adjusted efficiency ratio1 of 47.35%
Balance Sheet & Credit Quality
	Total loans and leases	$	6,620,602	$	5,596,512	$	5,309,101	Balance Sheet
	Total deposits		6,953,690		5,917,092		5,612,456	• Total assets of $8.9 billion
	Net charge-offs		5,430		4,267		1,791
	Allowance for credit losses (ACL) to total loans and		1.60%		1.66%		1.51%	• Average total loan and lease growth 17.1%
	leases held for investment
Select Ratios								• Average total deposit growth 18.6%
	Efficiency ratio1		53.75%		52.92%		55.07%
	Return on average assets (ROAA)		1.30%		1.41%		1.13%	• Credit quality metrics in line with
	Return on average stockholders' equity		12.11%		12.99%		10.57%	expectations; through-the-cycle approach
	Return on average tangible common equity1		16.15%		16.78%		14.17%	to credit risk management
	Net Interest Margin (NIM)		4.46%		4.32%		4.03%
	Tangible common equity to tangible assets1		8.18%		8.87%		8.10%	• Regulatory capital ratios remain solid
	Common Equity Tier 1		10.08%		10.58%		10.24%

CEO/President Commentary

Roberto R. Herencia, Executive Chairman and CEO of Byline Bancorp, commented, “We successfully completed the core system conversion and integration of our recent acquisition of Inland Bancorp, which we believe has strengthened the return profile of the company. With the expansion of our footprint and the continued execution of our strategic priorities, we see opportunities to leverage our products and services, and deliver enhanced stockholder value for years to come."

Alberto J. Paracchini, President of Byline Bancorp, added, “Adjusted third quarter results were highlighted by robust earnings, strong profitability, net interest margin expansion, solid deposit and loan growth, and controlled expenses. I want to thank our employees, who once again enabled our strong performance through their hard work,” said Mr. Paracchini.

(1)Represents non-GAAP financial measures. See “Reconciliation of non-GAAP Financial Measures” for a reconciliation to the most directly comparable GAAP financial measure.

(2)Recast due to the adoption of ASU 2016-13 Financial Instruments - Credit Losses on December 31, 2022, which was applied retrospectively to January 1, 2022. Refer to our Annual Report on Form 10-K for the year ended December 31, 2022 for additional information on the adoption of the standard.

Byline Bancorp, Inc.

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STATEMENTS OF OPERATIONS HIGHLIGHTS

Net Interest Income

Net interest income for the third quarter of 2023 was $92.5 million, an increase of $16.3 million, or 21.4%, from the second quarter of 2023. The increase in net interest income was primarily due to an increase of $26.3 million in interest income and fees on loans and leases due to loans acquired and higher yields; partially offset by an increase of $12.4 million in deposit interest expense due to deposits assumed and higher rates on deposits.

Tax-equivalent net interest margin1 for the third quarter of 2023 was 4.47%, an increase of 14 basis points compared to the second quarter of 2023. Total net loan accretion income impact on the margin contributed 50 basis points to the net interest margin for the third quarter of 2023 compared to three basis points for the second quarter of 2023.

The average cost of total deposits was 2.13% for the third quarter of 2023, an increase of 43 basis points compared to the second quarter of 2023, as a result of higher rates on money market accounts and time deposits. Average non-interest-bearing demand deposits were 28.8% of average total deposits for the third quarter of 2023 compared to 31.7% during the second quarter of 2023.

Provision for Credit Losses

The provision for credit losses was $8.8 million for the third quarter of 2023, an increase of $3.0 million compared to $5.8 million for the second quarter of 2023, mainly attributed to a $2.7 million provision allocated for acquired non-credit-deteriorated loans resulting from acquisition accounting. The provision for credit losses is comprised of a provision for loan and lease losses of $7.9 million and a provision for unfunded commitments of $938,000.

Non-interest Income

Non-interest income for the third quarter of 2023 was $12.4 million, a decrease of $1.9 million, or 13.4%, compared to $14.3 million for the second quarter of 2023. The decrease in total non-interest income was primarily due to a decrease of $2.8 million in the valuation of the loan servicing asset reflecting higher discount rates and higher prepayment rates, partially offset by an increase of $769,000, or 13.5%, in the net gain on sales of loans. During the third quarter of 2023, we sold $101.6 million of U.S. government guaranteed loans compared to $85.9 million during the second quarter of 2023.

Non-interest Expense

Non-interest expense for the third quarter of 2023 was $57.9 million, an increase of $8.6 million, or 17.4%, from $49.3 million for the second quarter of 2023. The increase in total non-interest expense was mainly due to an increase of $5.3 million in salaries and employee benefits and an increase of $2.2 million in data processing, both primarily driven by merger-related expenses.

Our efficiency ratio was 53.75% for the third quarter of 2023 compared to 52.92% for the second quarter of 2023. Excluding significant items, our adjusted efficiency ratio1 for the third quarter 2023 was 47.35%, compared to 51.39% for the second quarter of 2023.

Income Taxes

We recorded income tax expense of $9.9 million during the third quarter of 2023, compared to $9.2 million during the second quarter of 2023. The effective tax rate was 26.0% and 26.1% for the third quarter of 2023 and second quarter of 2023, respectively.

(1) Represents non-GAAP financial measures. See “Reconciliation of non-GAAP Financial Measures” for a reconciliation of our non-GAAP measures to the most directly comparable GAAP financial measure.

Byline Bancorp, Inc.

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STATEMENTS OF FINANCIAL CONDITION HIGHLIGHTS

Assets

Total assets were $8.9 billion as of September 30, 2023, an increase of $1.4 billion, or 18.1%, compared to $7.6 billion at June 30, 2023.

The current quarter increase was primarily due to an increase in net loans and leases of $1.0 billion mainly due to the acquisition; an increase in securities available-for-sale of $114.2 million, driven by increases in acquired securities; and an increase in cash and cash equivalents of $108.7 million mainly to support loan and lease portfolio growth and customer-related activities.

Non-performing loans and leases were $52.1 million at September 30, 2023, an increase of $13.8 million from $38.3 million at June 30, 2023. The increase was primarily the result of $13.7 million of non-performing acquired purchased credit deteriorated (PCD) loans.

Allowance for Credit Losses ("ACL") - Loans and Leases

ACL was $105.7 million as of September 30, 2023, an increase of $13.0 million, or 14.1%, from $92.7 million at June 30, 2023. The increase includes $10.6 million for PCD loans and a $2.7 million provision for acquired non-credit-deteriorated loans, as a result of the recent acquisition. Additional provision for originated loans and leases and an increase in individually assessed impairments were reduced by net charge-offs.

Net charge-offs of loans and leases during the third quarter of 2023 were $5.4 million, or 0.33% of average loans and leases, on an annualized basis. This was an increase of $1.1 million compared to net charge-offs of $4.3 million, or 0.31% of average loans and leases, during the second quarter of 2023.

Deposits and Other Liabilities

Total deposits increased to $7.0 billion at September 30, 2023 compared to $5.9 billion at June 30, 2023. Non-interest-bearing deposits were 28.2% and 30.3% of total deposits at September 30, 2023 and June 30, 2023, respectively. Estimated total uninsured deposits were $1.8 billion and $1.5 billion as of September 30, 2023 and June 30, 2023, and represented 26.1% and 25.9% of total deposits, respectively. The increase in deposits in the current quarter was mainly due to the deposits assumed and increased deposit campaigns. The increase in time deposits of $327.9 million was principally due to increased personal time deposits. The increase in money market demand accounts of $462.2 million was due to increases in consumer and commercial deposits. The increase in non-interest-bearing demand deposits of $166.1 million was mainly due to increases in assumed commercial deposits.

Total borrowings and other liabilities were $1.1 billion at September 30, 2023, an increase of $225.1 million from $844.7 million at June 30, 2023, primarily driven by increases in Federal Home Loan Bank advances, assumed junior subordinated debentures, accrued expenses and other liabilities.

Stockholders’ Equity

Total stockholders’ equity was $919.9 million at September 30, 2023, an increase of $106.0 million from $813.9 million at June 30, 2023. The increase was primarily due to stock consideration issued in connection with the acquisition.

(1) Represents non-GAAP financial measures. See “Reconciliation of non-GAAP Financial Measures” for a reconciliation of our non-GAAP measures to the most directly comparable GAAP financial measure.

Byline Bancorp, Inc.

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Conference Call, Webcast and Slide Presentation

We will host a conference call and webcast at 9:00 a.m. Central Time on Friday, October 27, 2023, to discuss our quarterly financial results. Analysts and investors may participate in the question-and-answer session. The call can be accessed via telephone at (833) 470-1428; passcode 719791. A recorded replay can be accessed through November 10, 2023, by dialing (866) 813-9403; passcode: 404695.

A slide presentation relating to our third quarter 2023 results will be accessible prior to the conference call. The slide presentation and webcast of the conference call can be accessed on our investor relations websiteatwww.bylinebancorp.com.

About Byline Bancorp, Inc.

Headquartered in Chicago, Byline Bancorp, Inc. is the parent company of Byline Bank, a full service commercial bank serving small- and medium-sized businesses, financial sponsors, and consumers. Byline Bank has approximately $8.9 billion in assets and operates 48 branch locations throughout the Chicago and Milwaukee metropolitan areas. Byline Bank offers a broad range of commercial and retail banking products and services including small ticket equipment leasing solutions and is one of the top Small Business Administration lenders in the United States.

Forward-Looking Statements

This communication contains forward-looking statements within the meaning of the U.S. federal securities laws. Forward-looking statements include, without limitation, statements concerning plans, estimates, calculations, forecasts and projections with respect to the anticipated future performance of the Company. These statements are often, but not always, made through the use of words or phrases such as ‘‘may’’, ‘‘might’’, ‘‘should’’, ‘‘could’’, ‘‘predict’’, ‘‘potential’’, ‘‘believe’’, ‘‘expect’’, ‘‘continue’’, ‘‘will’’, ‘‘anticipate’’, ‘‘seek’’, ‘‘estimate’’, ‘‘intend’’, ‘‘plan’’, ‘‘projection’’, ‘‘would’’, ‘‘annualized’’, “target” and ‘‘outlook’’, or the negative version of those words or other comparable words or phrases of a future or forward-looking nature. Forward-looking statements involve estimates and known and unknown risks, and reflect various assumptions and involve elements of subjective judgment and analysis, which may or may not prove to be correct, and which are subject to uncertainties and contingencies outside the control of Byline and its respective affiliates, directors, employees and other representatives, which could cause actual results to differ materially from those presented in this communication.

No representations, warranties or guarantees are or will be made by Byline as to the reliability, accuracy or completeness of any forward-looking statements contained in this communication or that such forward-looking statements are or will remain based on reasonable assumptions. You should not place undue reliance on any forward-looking statements contained in this communication.

Certain risks and important factors that could affect Byline’s future results are identified in our Annual Report on Form 10-K and other reports we file with the Securities and Exchange Commission, including among other things under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2022. Any forward-looking statement speaks only as of the date on which it is made, and Byline undertakes no obligation to update any forward-looking statement, whether to reflect events or circumstances after the date on which the statement is made, to reflect new information or the occurrence of unanticipated events, or otherwise unless required under the federal securities laws.

Contacts:

Investors/Media:

Brooks Rennie

Investor Relations Director

312-660-5805

brennie@bylinebank.com

Byline Bancorp, Inc.

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BYLINE BANCORP, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (unaudited)

							Recast
	September 30,			June 30,			September 30,
(dollars in thousands)	2023			2023			2022
ASSETS
Cash and due from banks	$	71,248		$	59,564		$	56,546
Interest bearing deposits with other banks		357,640			260,621			159,744
Cash and cash equivalents		428,888			320,185			216,290
Equity and other securities, at fair value		7,902			18,473			7,279
Securities available-for-sale, at fair value		1,239,929			1,125,700			1,181,654
Securities held-to-maturity, at amortized cost		1,157			2,158			3,877
Restricted stock, at cost		30,505			24,377			27,077
Loans held for sale		7,299			25,995			33,975
Loans and leases:
Loans and leases		6,613,303			5,570,517			5,275,126
Allowance for credit losses - loans and leases		(105,696	)		(92,665	)		(79,704	)
Net loans and leases		6,507,607			5,477,852			5,195,422
Servicing assets, at fair value		19,743			21,715			21,127
Premises and equipment, net		67,121			56,304			59,049
Other real estate owned, net		1,671			2,265			4,402
Goodwill and other intangible assets, net		205,028			155,977			160,484
Bank-owned life insurance		96,268			83,222			81,592
Deferred tax assets, net		89,841			66,895			95,831
Accrued interest receivable and other assets		240,409			194,572			179,218
Total assets	$	8,943,368		$	7,575,690		$	7,267,277
LIABILITIES AND STOCKHOLDERS’ EQUITY
LIABILITIES
Non-interest-bearing demand deposits	$	1,959,855		$	1,793,749		$	2,142,183
Interest-bearing deposits		4,993,835			4,123,343			3,470,273
Total deposits		6,953,690			5,917,092			5,612,456
Other borrowings		713,233			574,922			653,954
Subordinated notes, net		73,822			73,778			73,648
Junior subordinated debentures issued to    capital trusts, net		70,336			37,557			37,232
Accrued expenses and other liabilities		212,342			158,399			154,182
Total liabilities		8,023,423			6,761,748			6,531,472
STOCKHOLDERS’ EQUITY
Common stock		450			391			389
Additional paid-in capital		708,615			599,718			597,049
Retained earnings		403,368			379,078			314,800
Treasury stock		(50,329	)		(50,383	)		(51,535	)
Accumulated other comprehensive loss, net of tax		(142,159	)		(114,862	)		(124,898	)
Total stockholders’ equity		919,945			813,942			735,805
Total liabilities and stockholders’ equity	$	8,943,368		$	7,575,690		$	7,267,277

Byline Bancorp, Inc.

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BYLINE BANCORP, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited)

	Three Months Ended
							Recast
(dollars in thousands,	September 30,			June 30,			September 30,
except per share data)	2023			2023			2022
INTEREST AND DIVIDEND INCOME
Interest and fees on loans and leases	$	125,465		$	99,134		$	72,635
Interest on securities		8,415			6,559			6,402
Other interest and dividend income		2,710			1,579			626
Total interest and dividend income		136,590			107,272			79,663
INTEREST EXPENSE
Deposits		37,163			24,723			5,971
Other borrowings		3,981			4,241			3,232
Subordinated notes and debentures		2,994			2,142			1,825
Total interest expense		44,138			31,106			11,028
Net interest income		92,452			76,166			68,635
PROVISION FOR CREDIT LOSSES		8,803			5,790			7,208
Net interest income after provision for credit losses		83,649			70,376			61,427
NON-INTEREST INCOME
Fees and service charges on deposits		2,372			2,233			2,128
Loan servicing revenue		3,369			3,377			3,422
Loan servicing asset revaluation		(3,646	)		(865	)		(2,342	)
ATM and interchange fees		1,205			1,112			1,007
Net realized losses on securities available-for-sale		—			—			(2	)
Change in fair value of equity securities, net		(313	)		193			(581	)
Net gains on sales of loans		6,473			5,704			5,580
Wealth management and trust income		939			1,039			995
Other non-interest income		1,977			1,498			1,836
Total non-interest income		12,376			14,291			12,043
NON-INTEREST EXPENSE
Salaries and employee benefits		34,969			29,642			29,587
Occupancy and equipment expense, net		5,314			4,404			3,919
Impairment charge on assets held for sale					—			—
Loan and lease related expenses		836			488			530
Legal, audit, and other professional fees		3,805			3,675			2,733
Data processing		6,472			4,272			3,370
Net loss recognized on other real estate    owned and other related expenses		111			288			275
Other intangible assets amortization expense		1,551			1,455			1,611
Other non-interest expense		4,833			5,104			4,016
Total non-interest expense		57,891			49,328			46,041
INCOME BEFORE PROVISION FOR INCOME TAXES		38,134			35,339			27,429
PROVISION FOR INCOME TAXES		9,912			9,232			7,020
NET INCOME	$	28,222		$	26,107		$	20,409
EARNINGS PER COMMON SHARE
Basic	$	0.66		$	0.70		$	0.55
Diluted	$	0.65		$	0.70		$	0.55

Byline Bancorp, Inc.

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BYLINE BANCORP, INC. AND SUBSIDIARIES

SELECTED FINANCIAL DATA (unaudited)

	As of or For the Three Months Ended
							Recast
(dollars in thousands, except share	September 30,			June 30,			September 30,
and per share data)	2023			2023			2022
Earnings per Common Share
Basic earnings per common share	$	0.66		$	0.70		$	0.55
Diluted earnings per common share	$	0.65		$	0.70		$	0.55
Adjusted diluted earnings per common share(1)(3)	$	0.77		$	0.73		$	0.55
Weighted average common shares outstanding (basic)		43,025,927			37,034,626			36,851,973
Weighted average common shares outstanding (diluted)		43,458,110			37,337,906			37,371,159
Common shares outstanding		43,719,203			37,752,002			37,465,902
Cash dividends per common share	$	0.09		$	0.09		$	0.09
Dividend payout ratio on common stock		13.85	%		12.86	%		16.36	%
Tangible book value per common share(1)	$	16.35		$	17.43		$	15.36
Key Ratios and Performance Metrics (annualized where applicable)
Net interest margin, fully taxable equivalent (1)(4)		4.47	%		4.33	%		4.04	%
Average cost of deposits		2.13	%		1.70	%		0.43	%
Efficiency ratio(1)(2)		53.75	%		52.92	%		55.07	%
Adjusted efficiency ratio(1)(2)(3)		47.35	%		51.39	%		55.07	%
Non-interest income to total revenues(1)		11.81	%		15.80	%		14.93	%
Non-interest expense to average assets		2.66	%		2.67	%		2.56	%
Adjusted non-interest expense to average assets(1)(3)		2.35	%		2.60	%		2.56	%
Return on average stockholders' equity		12.11	%		12.99	%		10.57	%
Adjusted return on average stockholders' equity(1)(3)		14.30	%		13.56	%		10.57	%
Return on average assets		1.30	%		1.41	%		1.13	%
Adjusted return on average assets(1)(3)		1.53	%		1.48	%		1.13	%
Pre-tax pre-provision return on average assets(1)		2.16	%		2.23	%		1.93	%
Adjusted pre-tax pre-provision return on average assets(1)(3)		2.46	%		2.30	%		1.93	%
Return on average tangible common stockholders' equity(1)		16.15	%		16.78	%		14.17	%
Adjusted return on average tangible common stockholders' equity(1)(3)		18.95	%		17.50	%		14.17	%
Non-interest-bearing deposits to total deposits		28.18	%		30.31	%		38.17	%
Loans and leases held for sale and loans and lease held for investment to total deposits		95.21	%		94.58	%		94.59	%
Deposits to total liabilities		86.67	%		87.51	%		85.93	%
Deposits per branch	$	144,869		$	155,713		$	147,696
Asset Quality Ratios
Non-performing loans and leases to total loans and leases held for investment,   net before ACL		0.79	%		0.69	%		0.80	%
ACL to total loans and leases held for investment, net before ACL		1.60	%		1.66	%		1.51	%
Net charge-offs to average total loans and leases held for investment,   net before ACL - loans and leases		0.33	%		0.31	%		0.14	%
Capital Ratios
Common equity to total assets		10.29	%		10.74	%		10.12	%
Tangible common equity to tangible assets(1)		8.18	%		8.87	%		8.10	%
Leverage ratio		10.75	%		10.74	%		10.30	%
Common equity tier 1 capital ratio		10.08	%		10.58	%		10.24	%
Tier 1 capital ratio		11.12	%		11.22	%		10.91	%
Total capital ratio		13.17	%		13.52	%		13.02	%

(1) Represents a non-GAAP financial measure. See “Reconciliation of non-GAAP Financial Measures” for a reconciliation of our non-GAAP measures to the most directly comparable GAAP financial measure.

(2) Represents non-interest expense less amortization of intangible assets divided by net interest income and non-interest income.

(3) Calculation excludes merger-related expenses and impairment charges on assts held for sale and ROU assets

(4) Interest income and rates include the effects of a tax equivalent adjustment to adjust tax exempt investment income on tax exempt investment securities to a fully taxable basis, assuming a federal income tax rate of 21%.

Byline Bancorp, Inc.

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BYLINE BANCORP, INC. AND SUBSIDIARIES

QUARTER-TO-DATE STATEMENT OF AVERAGE INTEREST-EARNING ASSETS AND AVERAGE INTEREST-BEARING LIABILITIES (unaudited)

	For the Three Months Ended
	September 30, 2023								June 30, 2023								Recast September 30, 2022
(dollars in thousands)	Average Balance(5)			Interest Inc / Exp		Avg. Yield / Rate			Average Balance(5)			Interest Inc / Exp		Avg. Yield / Rate			Average Balance(5)			Interest Inc / Exp		Avg. Yield / Rate
ASSETS
Cash and cash equivalents	$	195,019		$	1,724		3.51	%	$	135,003		$	1,041		3.09	%	$	77,522		$	210		1.08	%
Loans and leases(1)		6,484,875			125,465		7.68	%		5,535,593			99,134		7.18	%		5,217,779			72,635		5.52	%
Taxable securities		1,371,979			8,465		2.45	%		1,250,780			6,324		2.03	%		1,306,024			5,963		1.81	%
Tax-exempt securities(2)		168,805			1,184		2.78	%		151,205			980		2.60	%		162,591			1,083		2.64	%
Total interest-earning assets	$	8,220,678		$	136,838		6.60	%	$	7,072,581		$	107,479		6.10	%	$	6,763,916		$	79,891		4.69	%
Allowance for credit losses -   loans and leases		(108,315	)							(92,804	)							(74,383	)
All other assets		521,982								424,122								447,939
TOTAL ASSETS	$	8,634,345							$	7,403,899							$	7,137,472
LIABILITIES AND STOCKHOLDERS’    EQUITY
Deposits
Interest checking	$	579,917		$	2,208		1.51	%	$	541,036		$	2,175		1.61	%	$	583,777		$	1,077		0.73	%
Money market accounts		2,040,476			16,676		3.24	%		1,534,463			10,799		2.82	%		1,391,923			3,358		0.96	%
Savings		594,555			228		0.15	%		575,254			220		0.15	%		673,966			247		0.15	%
Time deposits		1,706,531			18,051		4.20	%		1,328,679			11,529		3.48	%		687,124			1,289		0.74	%
Total interest-bearing   deposits		4,921,479			37,163		3.00	%		3,979,432			24,723		2.49	%		3,336,790			5,971		0.71	%
Other borrowings		463,561			3,981		3.41	%		509,419			4,241		3.34	%		607,471			3,232		2.11	%
Subordinated notes and   debentures		144,171			2,994		8.24	%		111,255			2,142		7.72	%		110,799			1,825		6.54	%
Total borrowings		607,732			6,975		4.55	%		620,674			6,383		4.12	%		718,270			5,057		2.79	%
Total interest-bearing liabilities	$	5,529,211		$	44,138		3.17	%	$	4,600,106		$	31,106		2.71	%	$	4,055,060		$	11,028		1.08	%
Non-interest-bearing   demand deposits		1,987,996								1,848,538								2,198,095
Other liabilities		192,860								148,983								118,496
Total stockholders’ equity		924,278								806,272								765,821
TOTAL LIABILITIES AND    STOCKHOLDERS’ EQUITY	$	8,634,345							$	7,403,899							$	7,137,472
Net interest spread(3)							3.43	%							3.39	%							3.61	%
Net interest income, fully   taxable equivalent				$	92,700							$	76,373							$	68,863
Net interest margin, fully   taxable equivalent(2)(4)							4.47	%							4.33	%							4.04	%
Less: Tax-equivalent adjustment					248		0.01	%					207		0.01	%					228		0.01	%
Net interest income				$	92,452							$	76,166							$	68,635
Net interest margin(4)							4.46	%							4.32	%							4.03	%
Net loan accretion impact   on margin				$	10,276		0.50	%				$	611		0.03	%				$	1,371		0.08	%

(1) Loan and lease balances are net of deferred origination fees and costs and initial direct costs. Non-accrual loans and leases are included in total loan and lease balances.

(2) Interest income and rates include the effects of a tax equivalent adjustment to adjust tax exempt investment income on tax exempt investment securities to a fully taxable basis, assuming a federal income tax rate of 21%.

(3) Represents the average rate earned on interest-earning assets minus the average rate paid on interest-bearing liabilities.

(4) Represents net interest income (annualized) divided by total average earning assets.

(5) Average balances are average daily balances.

Byline Bancorp, Inc.

Page 9 of 13

BYLINE BANCORP, INC. AND SUBSIDIARIES

SELECTED BALANCE SHEET TABLES AND FINANCIAL RATIOS (unaudited)

The following table presents our allocation of originated, purchased credit deteriorated (PCD), and acquired non-credit-deteriorated loans and leases at the dates indicated:

													Recast
	September 30, 2023						June 30, 2023						September 30, 2022
(dollars in thousands)	Amount			% of Total			Amount			% of Total			Amount			% of Total
Originated loans and leases
Commercial real estate	$	1,837,531			27.8	%	$	1,806,531			32.4	%	$	1,659,218			31.5	%
Residential real estate		454,456			6.9	%		453,880			8.1	%		409,926			7.8	%
Construction, land development, and    other land		406,334			6.1	%		387,623			7.0	%		456,276			8.5	%
Commercial and industrial		2,286,058			34.6	%		2,086,274			37.4	%		1,940,236			36.8	%
Installment and other		2,968			0.0	%		3,582			0.1	%		999			0.0	%
Leasing financing receivables		641,032			9.7	%		604,437			10.9	%		492,744			9.3	%
Total originated loans and leases	$	5,628,379			85.1	%	$	5,342,327			95.9	%	$	4,959,399			94.0	%
Purchased credit deteriorated loans
Commercial real estate	$	154,573			2.3	%	$	30,724			0.6	%	$	49,649			0.9	%
Residential real estate		47,485			0.7	%		26,012			0.5	%		35,309			0.7	%
Construction, land development, and    other land		29,587			0.5	%		320			0.0	%		1,131			0.0	%
Commercial and industrial		21,014			0.3	%		1,726			0.0	%		2,345			0.1	%
Installment and other		125			0.0	%		129			0.0	%		149			0.0	%
Total purchased credit deteriorated loans	$	252,784			3.8	%	$	58,911			1.1	%	$	88,583			1.7	%
Acquired non-credit-deteriorated loans   and leases
Commercial real estate	$	296,656			4.5	%	$	126,191			2.3	%	$	159,928			3.0	%
Residential real estate		220,091			3.4	%		25,055			0.4	%		36,480			0.7	%
Construction, land development, and    other land		87,087			1.3	%		—			0.0	%		187			0.0	%
Commercial and industrial		127,253			1.9	%		16,750			0.3	%		27,249			0.5	%
Installment and other		153			0.0	%		25			0.0	%		216			0.0	%
Leasing financing receivables		900			0.0	%		1,258			0.0	%		3,084			0.1	%
Total acquired non-credit-deteriorated    loans and leases	$	732,140			11.1	%	$	169,279			3.0	%	$	227,144			4.3	%
Total loans and leases	$	6,613,303			100.0	%	$	5,570,517			100.0	%	$	5,275,126			100.0	%
Allowance for credit losses - loans and leases		(105,696	)					(92,665	)					(79,704	)
Total loans and leases, net of allowance for    credit losses - loans and leases	$	6,507,607					$	5,477,852					$	5,195,422

The following table presents the balance and activity within the allowance for credit losses - loans and lease for the periods indicated:

	Three Months Ended
							Recast
	September 30,			June 30,			September 30,
(dollars in thousands)	2023			2023			2022
ACL - loans and leases, beginning of period	$	92,665		$	90,465		$	74,048
Adjustment for acquired PCD loans		10,596			—			—
Provision for credit losses - loans and leases		7,865			6,467			7,447
Net charge-offs - loans and leases		(5,430	)		(4,267	)		(1,791	)
ACL - loans and leases, end of period	$	105,696		$	92,665		$	79,704
Net charge-offs - loans and leases to average total    loans and leases held for investment, net before ACL		0.33	%		0.31	%		0.14	%
Provision for credit losses - loans and leases    to net charge-offs - loans and leases during the period		1.45	x		1.52	x		4.16	x

Byline Bancorp, Inc.

Page 10 of 13

BYLINE BANCORP, INC. AND SUBSIDIARIES

SELECTED BALANCE SHEET TABLES AND FINANCIAL RATIOS (unaudited)

The following table presents the amounts of non-performing loans and leases and other real estate owned at the date indicated:

										September 30, 2023
							Recast			Change from
(dollars in thousands)	September 30, 2023			June 30, 2023			September 30, 2022			June 30, 2023			September 30, 2022
Non-performing assets:
Non-accrual loans and leases	$	52,070		$	38,273		$	41,942			36.0	%		24.1	%
Past due loans and leases 90 days or more    and still accruing interest		—			—			—		—%			—%
Total non-performing loans and leases	$	52,070		$	38,273		$	41,942			36.0	%		24.1	%
Other real estate owned		1,671			2,265			4,402			(26.2	)%		(62.0	)%
Total non-performing assets	$	53,741		$	40,538		$	46,344			32.6	%		16.0	%
Total non-performing loans and leases as a    percentage of total loans and leases		0.79	%		0.69	%		0.80	%
Total non-performing assets as a percentage    of total assets		0.60	%		0.54	%		0.64	%
Allowance for credit losses - loans and lease    as a percentage of non-performing    loans and leases		202.99	%		242.12	%		190.03	%
Non-performing assets guaranteed by    U.S. government:
Non-accrual loans guaranteed	$	3,588		$	2,472		$	1,676			45.1	%		114.1	%
Past due loans 90 days or more and still    accruing interest guaranteed		—			—			—		—%			—%
Total non-performing loans guaranteed	$	3,588		$	2,472		$	1,676			45.1	%		114.1	%
Total non-performing loans and leases    not guaranteed as a percentage of total    loans and leases		0.73	%		0.64	%		0.76	%
Total non-performing assets not guaranteed    as a percentage of total assets		0.56	%		0.50	%		0.61	%

The following table presents the composition of deposits at the dates indicated:

							September 30, 2023
							Change from
(dollars in thousands)	September 30, 2023		June 30, 2023		September 30, 2022		June 30, 2023			September 30, 2022
Non-interest-bearing demand deposits	$	1,959,855	$	1,793,749	$	2,142,183		9.3	%		(8.5	)%
Interest-bearing checking accounts		592,771		530,775		616,139		11.7	%		(3.8	)%
Money market demand accounts		2,062,252		1,600,043		1,485,815		28.9	%		38.8	%
Other savings		581,073		562,706		669,734		3.3	%		(13.2	)%
Time deposits (below $250,000)		1,446,485		1,214,717		586,198		19.1	%		146.8	%
Time deposits ($250,000 and above)		311,254		215,102		112,387		44.7	%		176.9	%
Total deposits	$	6,953,690	$	5,917,092	$	5,612,456		17.5	%		23.9	%

Byline Bancorp, Inc.

Page 11 of 13

BYLINE BANCORP, INC. AND SUBSIDIARIES

RECONCILIATION OF NON-GAAP FINANCIAL MEASURES (unaudited)

Non-GAAP Financial Measures

This release contains certain financial information determined by methods other than in accordance with accounting principles generally accepted in the United States of America (“GAAP”). These measures include adjusted net income, adjusted diluted earnings per share, adjusted efficiency ratio, adjusted non-interest expense to average assets, tax-equivalent net interest margin, total revenue, non-interest income to total revenues, adjusted return on average stockholders’ equity, adjusted return on average assets, pre-tax pre-provision return on average assets, adjusted pre-tax pre-provision return on average assets, tangible book value per common share, tangible common equity to tangible assets, return on average tangible common stockholders' equity, and adjusted return on average tangible common stockholders' equity. Management believes that these non-GAAP financial measures provide useful information to management and investors that is supplementary to the Company’s financial condition, results of operations and cash flows computed in accordance with GAAP; however, management acknowledges that our non-GAAP financial measures have a number of limitations. As such, these disclosures should not be viewed as a substitute for results determined in accordance with GAAP financial measures that we and other companies use. Management also uses these measures for peer comparison. See below in the financial schedules included in this press release for a reconciliation of the non-GAAP financial measures to the comparable GAAP financial measures. Additionally, please refer to the Company’s Annual Report on Form 10-K for the detailed definitions of these non-GAAP financial measures.

	As of or For the Three Months Ended
							Recast
	September 30,			June 30,			September 30,
(dollars in thousands, except per share data)	2023			2023			2022
Net income and earnings per share excluding significant items
Reported Net Income	$	28,222		$	26,107		$	20,409
Significant items:
Impairment charges on ROU assets		394			—			—
Merger-related expenses		6,307			1,391			—
Tax benefit		(1,617	)		(230	)		—
Adjusted Net Income	$	33,306		$	27,268		$	20,409
Reported Diluted Earnings per Share	$	0.65		$	0.70		$	0.55
Significant items:
Impairment charges on ROU assets		0.01			—			—
Merger-related expenses		0.15			0.04			—
Tax benefit		(0.04	)		(0.01	)		—
Adjusted Diluted Earnings per Share	$	0.77		$	0.73		$	0.55

Byline Bancorp, Inc.

Page 12 of 13

BYLINE BANCORP, INC. AND SUBSIDIARIES

RECONCILIATION OF NON-GAAP FINANCIAL MEASURES (continued) (unaudited)

	As of or For the Three Months Ended
							Recast
(dollars in thousands, except per share data,	September 30,			June 30,			September 30,
ratios annualized, where applicable)	2023			2023			2022
Adjusted non-interest expense:
Non-interest expense	$	57,891		$	49,328		$	46,041
Less: Significant items
Impairment charges on ROU assets		394			—			—
Merger-related expenses		6,307			1,391			—
Adjusted non-interest expense	$	51,190		$	47,937		$	46,041
Adjusted non-interest expense excluding    amortization of intangible assets:
Adjusted non-interest expense	$	51,190		$	47,937		$	46,041
Less: Amortization of intangible assets		1,551			1,455			1,611
Adjusted non-interest expense excluding    amortization of intangible assets	$	49,639		$	46,482		$	44,430
Pre-tax pre-provision net income:
Pre-tax income	$	38,134		$	35,339		$	27,429
Add: Provision for credit losses		8,803			5,790			7,208
Pre-tax pre-provision net income	$	46,937		$	41,129		$	34,637
Adjusted pre-tax pre-provision net income:
Pre-tax pre-provision net income	$	46,937		$	41,129		$	34,637
Add: Impairment charges on ROU assets		394			—			—
Add: Merger-related expenses		6,307			1,391			—
Adjusted pre-tax pre-provision net income	$	53,638		$	42,520		$	34,637
Tax equivalent net interest income
Net interest income	$	92,452		$	76,166		$	68,635
Add: Tax-equivalent adjustment		248			207			228
Net interest income, fully taxable equivalent	$	92,700		$	76,373		$	68,863
Total revenue:
Net interest income	$	92,452		$	76,166		$	68,635
Add: Non-interest income		12,376			14,291			12,043
Total revenue	$	104,828		$	90,457		$	80,678
Tangible common stockholders' equity:
Total stockholders' equity	$	919,945		$	813,942		$	735,805
Less: Goodwill and other intangibles		205,028			155,977			160,484
Tangible common stockholders' equity	$	714,917		$	657,965		$	575,321
Tangible assets:
Total assets	$	8,943,368		$	7,575,690		$	7,267,277
Less: Goodwill and other intangibles		205,028			155,977			160,484
Tangible assets	$	8,738,340		$	7,419,713		$	7,106,793
Average tangible common stockholders' equity:
Average total stockholders' equity	$	924,278		$	806,272		$	765,821
Less: Average goodwill and other intangibles		202,978			156,766			161,292
Average tangible common stockholders' equity	$	721,300		$	649,506		$	604,529
Average tangible assets:
Average total assets	$	8,634,345		$	7,403,899		$	7,137,472
Less: Average goodwill and other intangibles		202,978			156,766			161,292
Average tangible assets	$	8,431,367		$	7,247,133		$	6,976,180
Tangible net income available to common stockholders:
Net income available to common stockholders	$	28,222		$	26,107		$	20,409
Add: After-tax intangible asset amortization		1,137			1,067			1,181
Tangible net income available to common stockholders	$	29,359		$	27,174		$	21,590
Adjusted tangible net income available to common stockholders:
Tangible net income available to common stockholders	$	29,359		$	27,174		$	21,590
Impairment charges on ROU assets		394			—			—
Merger-related expenses		6,307			1,391			—
Tax benefit on significant items		(1,617	)		(230	)		—
Adjusted tangible net income available to common stockholders	$	34,443		$	28,335		$	21,590

Byline Bancorp, Inc.

Page 13 of 13

BYLINE BANCORP, INC. AND SUBSIDIARIES

RECONCILIATION OF NON-GAAP FINANCIAL MEASURES (continued) (unaudited)

	As of or For the Three Months Ended
							Recast
(dollars in thousands, except share and per share	September 30,			June 30,			September 30,
data, ratios annualized, where applicable)	2023			2023			2022
Pre-tax pre-provision return on average assets:
Pre-tax pre-provision net income	$	46,937		$	41,129		$	34,637
Average total assets		8,634,345			7,403,899			7,137,472
Pre-tax pre-provision return on average assets		2.16	%		2.23	%		1.93	%
Adjusted pre-tax pre-provision return on average assets:
Adjusted pre-tax pre-provision net income	$	53,638		$	42,520		$	34,637
Average total assets		8,634,345			7,403,899			7,137,472
Adjusted pre-tax pre-provision return on average assets		2.46	%		2.30	%		1.93	%
Net interest margin, fully taxable equivalent
Net interest income, fully taxable equivalent	$	92,700		$	76,373		$	68,863
Total average interest-earning assets		8,220,678			7,072,581			6,763,916
Net interest margin, fully taxable equivalent		4.47	%		4.33	%		4.04	%
Non-interest income to total revenues:
Non-interest income	$	12,376		$	14,291		$	12,043
Total revenues		104,828			90,457			80,678
Non-interest income to total revenues		11.81	%		15.80	%		14.93	%
Adjusted non-interest expense to average assets:
Adjusted non-interest expense	$	51,190		$	47,937		$	46,041
Average total assets		8,634,345			7,403,899			7,137,472
Adjusted non-interest expense to average assets		2.35	%		2.60	%		2.56	%
Adjusted efficiency ratio:
Adjusted non-interest expense excluding amortization of intangible assets	$	49,639		$	46,482		$	44,430
Total revenues		104,828			90,457			80,678
Adjusted efficiency ratio		47.35	%		51.39	%		55.07	%
Adjusted return on average assets:
Adjusted net income	$	33,306		$	27,268		$	20,409
Average total assets		8,634,345			7,403,899			7,137,472
Adjusted return on average assets		1.53	%		1.48	%		1.13	%
Adjusted return on average stockholders' equity:
Adjusted net income	$	33,306		$	27,268		$	20,409
Average stockholders' equity		924,278			806,272			765,821
Adjusted return on average stockholders' equity		14.30	%		13.56	%		10.57	%
Tangible common equity to tangible assets:
Tangible common equity	$	714,917		$	657,965		$	575,321
Tangible assets		8,738,340			7,419,713			7,106,793
Tangible common equity to tangible assets		8.18	%		8.87	%		8.10	%
Return on average tangible common stockholders' equity:
Tangible net income available to common stockholders	$	29,359		$	27,174		$	21,590
Average tangible common stockholders' equity		721,300			649,506			604,529
Return on average tangible common stockholders' equity		16.15	%		16.78	%		14.17	%
Adjusted return on average tangible common stockholders' equity:
Adjusted tangible net income available to common stockholders	$	34,443		$	28,335		$	21,590
Average tangible common stockholders' equity		721,300			649,506			604,529
Adjusted return on average tangible common stockholders' equity		18.95	%		17.50	%		14.17	%
Tangible book value per share:
Tangible common equity	$	714,917		$	657,965		$	575,321
Common shares outstanding		43,719,203			37,752,002			37,465,902
Tangible book value per share	$	16.35		$	17.43		$	15.36