19 21 65 59 74 150 0 113 186 83 84 84 248 157 56 Investor Presentation 1st Quarter 2025 Financial information

Legal Disclosures Forward-Looking Statements (p. 1 of 2) We have made forward-looking statements in this document, and in documents that we incorporate by reference, that are subject to risks and uncertainties. Forward-looking statements include information concerning possible or assumed future results of operations of the Company, the Bank, First Citizens Insurance or the Company on a consolidated basis. When we use words such as “believes,” “expects,” “anticipates,” or similar expressions, we are making forward-looking statements. Forward-looking statements may prove inaccurate. For a variety of reasons, actual results could differ materially from those contained in or implied by forward-looking statements: •Interest rates could change more rapidly or more significantly than we expect. •The economy could change significantly in an unexpected way, which would cause the demand for new loans and the ability of borrowers to repay outstanding loans to change in ways that our models do not anticipate. •The financial markets could suffer a significant disruption, which may have a negative effect on our financial condition and that of our borrowers, and on our ability to raise money by issuing new securities. •It could take us longer than we anticipate implementing strategic initiatives, including expansions, designed to increase revenues or manage expenses, or we may be unable to implement those initiatives at all. •Acquisitions and dispositions of assets and companies could affect us in ways that management has not anticipated. •We may become subject to new legal obligations or the resolution of litigation may have a negative effect on our financial condition or operating results. •We may become subject to new and unanticipated accounting, tax, regulatory or compliance practices or requirements. Failure to comply with any one or more of these requirements could have an adverse effect on our operations. •We could experience greater loan delinquencies than anticipated, adversely affecting our earnings and financial condition. •We could experience greater losses than expected due to the ever increasing volume of information theft and fraudulent scams impacting our customers and the banking industry. •We could lose the services of some or all of our key personnel, which would negatively impact our business because of their business development skills, financial expertise, lending experience, technical expertise and market area knowledge.

Legal Disclosures Forward-Looking Statements (p. 2 of 2) •The agricultural economy is subject to extreme swings in both the costs of resources and the prices received from the sale of products as a result of weather, government regulations, international trade agreements and consumer tastes, which could negatively impact certain of our customers. •Loan concentrations in certain industries could negatively impact our results, if financial results or economic conditions deteriorate. •Companies providing support services related to the exploration and drilling of the natural gas reserves in our market area may be affected by federal, state and local laws and regulations such as restrictions on production, permitting, changes in taxes and environmental protection, which could negatively impact our customers and, as a result, negatively impact our loan and deposit volume and loan quality. Additionally, the activities the companies providing support services related to the exploration and drilling of the natural gas reserves may be dependent on the market price of natural gas. As a result, decreases in the market price of natural gas could also negatively impact these companies, our customers. Additional factors are discussed in this Annual Report on Form 10-K under “Item 1A. Risk Factors.” These risks and uncertainties should be considered in evaluating forward-looking statements and undue reliance should not be placed on such statements. Forward-looking statements speak only as of the date they are made and the Company does not undertake to update forward-looking statements to reflect circumstances or events that occur after the date of the forward-looking statements or to reflect the occurrence of unanticipated events. Accordingly, past results and trends should not be used by investors to anticipate future results or trends.

About Citizens Financial Services, Inc.

Company Profile Lines of Business Retail Banking Commercial and Agricultural Consumer Fee Businesses Retail Banking with 44 branches and 29 ATMs Mobile & Online Banking C&I Lending SBA and USDA Lending Treasury Management Card & Payment Services Business Banking Home Lending Personal Lending Indirect Auto Lending Secured & Unsecured Consumer Loans Retail Plan Admin / Custody Services Business, Personal, & Life Insurance Institutional Life Insurance Brokerage & Advisory Services Trust Services Financial Highlights Assets: $3.0B Gross Loans: $2.3B Deposits: $2.4B YTD Return on Average Assets: 1.00% YTD Return on Average Tangible Common Equity : 14.09%(3) Company Overview (1) Market Cap as of April 28, 2025 (2) Branches & Employees data as of April 25, 2025 (3) Please see appendix for non-GAAP reconciliations Note: Holding Company data shown; Data as of March 31, 2025 Headquarters Mansfield, PA Founded 1872 Chartered 1932 Ticker NASDAQCM: CZFS Market Cap(1) $260.5 Branches(2) 44 Employees(2) 374 FT – 33 PT Institutional Ownership 26.31% 3 Mo. ADTV 10,880 52 Week H/L $75.40 / $38.52 Chairman R. Joseph Landy CEO, President & Vice Chairman Randall E. Black Executive VP & CFO Stephen J. Guillaume

Financial Highlights (1) Please see appendix for non-GAAP reconciliations MRQ – Highlights - YTD Profitability Balance Sheet Credit 2025Q1 vs. 2024Q4 March 31, 2025 Diluted EPS $1.60 Diluted EPS $1.60 Net Income $7.6 M Net Income $7.6 M Core ROATCE 14.09% Core ROATCE(1) 14.09% Net Interest Margin 3.30% vs. 3.26% Core ROAA (1) 1.00% vs. 1.06% YTD Core ROAA(1) 1.00% vs. 0.96% Efficiency Ratio 59.27% vs. 61.46% Total Assets $3.0B (0.3%) Growth Total Loans and Leases $2.3B (0.05%) Growth Total Deposits $2.4B (0.72%) Growth NPAs / Assets Ratio 0.91% vs. 0.95% NPLs / Gross Loans Ratio 1.08% vs. 1.12% Reserves / NPLs Ratio 88.5% vs. 83.5%

Experienced Leadership Executive Title Years of Banking Experience Joined FCCB Randall E. Black Vice Chairman, President & CEO 31 1993 Stephen J. Guillaume Executive VP & CFO 15 2009 David Z. Richards Jr. Sr Executive VP & Board Director 47 2017 Jeffrey L. Wilson Sr Executive VP & Chief Lending Officer 37 1987 LeeAnn Gephart Executive VP & Chief Banking Officer 18 2021 Jeffrey R White Executive VP & COO 7 2024

Investment Highlights Long history of creating shareholder value and operating successfully Tenured management with strong track record of operating high value companies Experienced, disciplined and prudent acquirer Strong geographic diversification presents opportunities Steady record of high profitability Diversity of interest earning assets Long-term focus on shareholder returns

For the past 16 years, Citizens Financial Services, Inc. has been ranked one of the top 100 best performing community banks in the nation with assets less than $2 billion. This ranking is based on a 3-year ROAE. Our 2012 performance ranked us as number ONE in the nation. We also continue to be ranked in the top 100 Ag lenders nationwide, 2nd for banks HQ’d in PA. In 2022 FCCB was included in the ABA Nasdaq Community Bank Index – an indication of our progress and leadership capabilities in the market. In 2017, Forbes Magazine began conducting customer satisfaction surveys for all banks across the nation. First Citizens Community Bank was voted “Best in State Bank” by our customers in a Forbes Magazine survey in 2018 and 2019. FCCB was celebrated for outstanding 2020 performance in the prestigious Bank Directors Performance Scorecard, placing 29th in the nation and as the highest-ranking Pennsylvania bank. In 2022 FCCB received the Bank On Certification, a certification promoted by the CFE Fund that is nationally awarded to banks that meet account criteria that ensures everyone has access to a safe, affordable transactional banking account. In 2020, Banking Mid Atlantic magazine ranked FCCB as the third bank in North Central, Pennsylvania for overall quality. In a 2021 Rivel Banking benchmark study, FCCB was ranked 5th in the state of Pennsylvania for the quality of our response to the COVID-19 pandemic. 2023 and 2024: FCCB was recognized by Newsweek and Plant-A Insights Group as one of the top 250 regional banks in the United States. This distinction was awarded based on a thorough evaluation of profitability, financial relevance, risk exposures, overall health, and stability, including social media and app store reviews. A Recognized High Performer

Business & Financial Highlights

Key Financial Highlights Top Tier Consolidated

Liquidity Position and Sources Note: Bank level regulatory data shown Liquidity Well-Managed to Cover Short-Term Needs Liquidity Sources March 31, 2025 December 31, 2024 $ in Thousands $ in Thousands Cash and Cash Equivalents $40,411 $45,827 FHLB Borrowing Capacity Remaining 616,996 551,861 Brokered Deposits Capacity 524,437 510,550 FRB Borrowing Capacity 49,101 33,284 Total $1,230,945 $1,141,522 Investments US Gov't & Agency $210,727 $220,351 MBS & CMO $134,639 $124,843 Municipals $102,792 $103,137 Corporates $11,230 $11,206 Less: Pledged Securities (362,098) -332,651 Net Unpledged Securities $97,290 $126,886 Total Liquidity Sources $1,328,235 $1,268,408

Deposit Mix Deposit Mix Analysis Note: Bank level regulatory data shown

Loan Portfolio Mix Loan Type Analysis Note: Bank level regulatory data shown

History of Successful Growth Total Asset Growth since 2000 ($000) Note: Dollars in thousands

Consistent & Attractive Returns Historical Core ROAA (1) & ROATCE (1) (1) Please see appendix for non-GAAP reconciliations

History of Strong Asset Quality Historical NPAs/Assets Trends NCOs/Avg Loans: 0.06% 0.03% 0.00% 0.03% 0.11% 0.03%

Note: Financial and transaction value shown as of announcement of transaction Successful Track Record of Prudent Acquisitions Transaction: FNB of Fredericksburg MidCoast Community Bancorp, Inc. HV Bancorp, Inc. Total Whole Bank Acquisitions Since January 1, 2015 Geography: Fredericksburg, PA Wilmington, DE Doylestown, PA -- Date Closed: 12/11/2015 4/17/2020 6/16/2023 -- Locations: 7 3 12 22 Purchase Price: Cash & Stock: $23.0 million Cash & Stock: $29.5 million Cash & Stock: $67.9 million -- Target Assets ($M): $232 $269 $571 $1,072 Target Loans ($M): $146 $231 $391 $769 Target Deposits ($M): $214 $213 $482 $909 CZFS Acquisitions since January 1, 2015

appendix

Non-GAAP Reconciliation – Tangible Book Value Dollars in Thousands For the Twelve Months Ended, For the Quarter Ended, Dollars in thousands 12/31/2022 12/31/2023 12/31/2024 6/30/2024 9/30/2024 12/31/2024 3/31/2025 Total common equity $200,147 $279,666 $299,734 $286,470 $298,654 $299,734 $308,296 Less: Total intangible assets 32,648 89,408 88,650 89,002 88,841 88,650 88,464 Tangible common equity $167,499 $190,258 $211,084 $197,468 $209,813 $211,084 $219,832 Total assets $2,333,393 $2,975,321 $3,025,724 $2,947,531 $3,026,468 $3,025,724 $3,016,338 Less: Total intangible assets 32,648 89,408 88,650 89,002 88,841 88,650 88,464 Tangible assets $2,300,745 $2,885,913 $2,937,074 $2,858,529 $2,937,627 $2,937,074 $2,927,874 Accumulated other comprehensive loss ($33,141) ($24,911) ($23,521) ($25,932) ($18,916) ($23,521) ($20,239) TCE / TA 7.28% 6.59% 7.19% 6.91% 7.14% 7.19% 7.51% TCE / TA (Excl. AOCI) 8.72% 7.46% 7.99% 7.82% 7.79% 7.99% 8.20% Tangible Book Value Per Share $41.29 $40.02 $44.35 $41.49 $44.08 $44.35 $46.19

Non-GAAP Reconciliation