PRESS RELEASE

FOR IMMEDIATE RELEASE

ACNB CORPORATION REPORTS

2023 THIRD QUARTER FINANCIAL RESULTS

2023 Third Quarter Highlights

Net Interest Income and Margin

Noninterest Income

Noninterest Expense

Loans and Asset Quality

Deposits and Borrowings

Stockholders’ Equity, Dividends and Share Repurchases

About ACNB Corporation

SAFE HARBOR AND FORWARD-LOOKING STATEMENTS - Should there be a material subsequent event prior to the filing of the Quarterly Report on Form 10-Q with the Securities and Exchange Commission, the financial information reported in this press release is subject to change to reflect the subsequent event. In addition to historical information, this press release may contain forward-looking statements. Examples of forward-looking statements include, but are not limited to, (a) projections or statements regarding future earnings, expenses, net interest income, other income, earnings or loss per share, asset mix and quality, growth prospects, capital structure, and other financial terms, (b) statements of plans and objectives of Management or the Board of Directors, and (c) statements of assumptions, such as economic conditions in the Corporation’s market areas. Such forward-looking statements can be identified by the use of forward-looking terminology such as “believes”, “expects”, “may”, “intends”, “will”, “should”, “anticipates”, or the negative of any of the foregoing or other variations thereon or comparable terminology, or by discussion of strategy. Forward-looking statements are subject to certain risks and uncertainties such as national, regional and local economic conditions, competitive factors, and regulatory limitations. Actual results may differ materially from those projected in the forward-looking statements. Such risks, uncertainties, and other factors that could cause actual results and experience to differ from those projected include, but are not limited to, the following: short-term and long-term effects of inflation and rising costs on the Corporation, customers and economy; the continuing banking instability caused by the recent failures and continuing financial uncertainty of various banks which may adversely impact the Corporation and its securities and loan values, deposit stability, capital adequacy, financial condition, operations, liquidity, and results of operations; effects of governmental and fiscal policies, as well as legislative and regulatory changes; effects of new laws and regulations (including laws and regulations concerning taxes, banking, securities and insurance) and their application with which the Corporation and its subsidiaries must comply; impacts of the capital and liquidity requirements of the Basel III standards; effects of changes in accounting policies and practices, as may be adopted by the regulatory agencies, as well as the Financial Accounting Standards Board and other accounting standard setters; ineffectiveness of the business strategy due to changes in current or future market conditions; future actions or inactions of the United States government, including the effects of short-term and long-term federal budget and tax negotiations and a failure to increase the government debt limit or a prolonged shutdown of the federal government; effects of economic conditions particularly with regard to the negative impact of any pandemic, epidemic or health-related crisis and the responses thereto on the operations of the Corporation and current customers, specifically the effect of the economy on loan customers’ ability to repay loans; effects of competition, and of changes in laws and regulations on competition, including industry consolidation and development of competing financial products and services; inflation, securities market and monetary fluctuations; risks of changes in interest rates on the level and composition of deposits, loan demand, and the values of loan collateral, securities, and interest rate protection agreements, as well as interest rate

risks; difficulties in acquisitions and integrating and operating acquired business operations, including information technology difficulties; challenges in establishing and maintaining operations in new markets; effects of technology changes; effects of general economic conditions and more specifically in the Corporation’s market areas; failure of assumptions underlying the establishment of reserves for credit losses and estimations of values of collateral and various financial assets and liabilities; acts of war or terrorism or geopolitical instability; disruption of credit and equity markets; ability to manage current levels of impaired assets; loss of certain key officers; ability to maintain the value and image of the Corporation’s brand and protect the Corporation’s intellectual property rights; continued relationships with major customers; and, potential impacts to the Corporation from continually evolving cybersecurity and other technological risks and attacks, including additional costs, reputational damage, regulatory penalties, and financial losses. We caution readers not to place undue reliance on these forward-looking statements. They only reflect Management’s analysis as of this date. The Corporation does not revise or update these forward-looking statements to reflect events or changed circumstances. Please carefully review the risk factors described in other documents the Corporation files from time to time with the SEC, including the Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q. Please also carefully review any Current Reports on Form 8-K filed by the Corporation with the SEC.

ACNB Corporation Financial Highlights

Selected Financial Data by Respective Quarter End

(Unaudited)

Dollars in thousands, except per share data			September 30, 2023						June 30, 2023						March 31, 2023						December 31, 2022						September 30, 2022
BALANCE SHEET DATA
Assets			$	2,388,522					$	2,378,151					$	2,410,933					$	2,525,507					$	2,654,153
Securities			501,063						518,093						568,232						620,250						571,796
Loans, total			1,615,966						1,573,817						1,531,626						1,538,610						1,527,128
Allowance for credit losses			19,264						19,148						19,485						17,861						17,952
Deposits			1,951,359						1,963,754						2,055,822						2,198,975						2,336,213
Allowance for unfunded commitments			1,962						2,132						2,011						92						92
Borrowings			153,388						132,703						76,294						62,954						65,691
Stockholders’ equity			255,638						257,069						255,841						245,042						232,370
INCOME STATEMENT DATA
Interest income			$	24,234					$	23,213					$	23,909					$	24,894					$	23,382
Interest expense			2,489						1,223						817						846						862
Net interest income			21,745						21,990						23,092						24,048						22,520
Provision for (reversal of ) credit losses			250						(273)						97						—						—
(Reversal of) provision for unfunded commitments			(171)						121						276						—						—
Net interest income after provisions for credit losses and unfunded commitments			21,666						22,142						22,719						24,048						22,520
Other income			6,297						6,194						4,984						5,423						5,849
Other expenses			16,336						16,281						16,282						16,673						15,320
Income before income taxes			11,627						12,055						11,421						12,798						13,049
Provision for income taxes			2,583						2,531						2,398						2,599						2,725
Net income			$	9,044					$	9,524					$	9,023					$	10,199					$	10,324
PROFITABILITY RATIOS
Loans held-for-investment to deposits			82.81		%				80.14		%				74.50		%				69.97		%				65.37		%
Return on average assets (annualized)			1.52		%				1.62		%				1.50		%				1.56		%				1.51		%
Return on average equity (annualized)			13.84		%				14.74		%				14.58		%				17.10		%				17.06		%
Efficiency ratio1			56.97		%				55.52		%				56.36		%				55.66		%				52.45		%
FTE Net interest margin			4.01		%				4.11		%				4.22		%				4.03		%				3.60		%
Yield on average earning assets			4.46		%				4.33		%				4.37		%				4.17		%				3.74		%
Yield on securities			2.24		%				2.24		%				2.46		%				2.30		%				2.05		%
Yield on loans			5.16		%				5.05		%				5.12		%				4.97		%				4.75		%
Cost of funds			0.47		%				0.23		%				0.15		%				0.14		%				0.14		%
PER SHARE DATA
Diluted earnings per share			$	1.06					$	1.12					$	1.06					$	1.20					$	1.20
Cash dividends paid per share			0.28						0.28						0.28						0.28						0.26
Tangible book value per share1			23.80						23.83						23.66						22.41						20.86
Tangible book value per share (ex-AOCI)1			31.43						30.64						29.76						29.23						28.23
CAPITAL RATIOS2
Tier 1 leverage ratio			11.97		%				11.79		%				11.09		%				9.91		%				9.33		%
Common equity tier 1 ratio			15.30		%				15.38		%				15.21		%				15.00		%				14.74		%
Tier 1 risk based capital ratio			15.59		%				15.72		%				15.56		%				15.36		%				15.10		%
Total risk based capital ratio			17.49		%				17.67		%				17.56		%				17.32		%				17.11		%
CREDIT QUALITY
Net charge-offs to average loans outstanding (annualized)			0.03		%				0.02		%				0.02		%				0.02		%				0.26		%
Total non-performing loans to loans held-for-investment3			0.22		%				0.23		%				0.25		%				0.25		%				0.26		%
Total non-performing assets to total assets4			0.17		%				0.17		%				0.18		%				0.17		%				0.16		%
Allowance for credit losses to loans held-for-investment			1.19		%				1.22		%				1.27		%				1.16		%				1.18		%

Consolidated Balance Sheets

(Unaudited)

Consolidated Income Statements

(Unaudited)

Average Balances, Income and Expenses, Yields and Rates

Non-GAAP Reconciliation