19 21 65 59 74 150 0 113 186 83 84 84 248 157 56 Investor Presentation 1st Quarter 2026 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 43 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: $3.03B Gross Loans: $2.30B Deposits: $2.44B YTD Return on Average Assets: 1.34% YTD Return on Average Tangible Common Equity : 16.15%(3) Company Overview (1) Market Cap as of April 23, 2026 (2) Branches & Employees data as of April 22, 2026 (3) Please see appendix for non-GAAP reconciliations Note: Holding Company data shown; Data as of March 31, 2026 Headquarters Mansfield, PA Founded 1872 Chartered 1932 Ticker NASDAQCM: CZFS Market Cap(1) $313.2 Branches(2) 43 Employees(2) 371 FT – 37 PT Institutional Ownership 29.22% 3 Mo. ADTV 8,789 52 Week H/L $69.58 / $49.99 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 2026Q1 vs. 2025Q4 March 31, 2026 Diluted EPS $2.16 Diluted EPS $2.16 Net Income $10.4M Net Income $10.4 M Core ROATCE 16.15% Core ROATCE(1) 16.15% Net Interest Margin 3.72% vs. 3.69% Core ROAA (1) 1.34% vs. 1.37% YTD Core ROAA(1) 1.34% vs. 1.37% Efficiency Ratio 54.98% vs. 54.03% Total Assets $3.0B (1.2%) Growth – Excluding student loan activity 0.99% growth Total Loans and Leases $2.3B (2.4%) Growth – Excluding brokered deposit growth 0.5% growth Total Deposits $2.4B 2.7% Growth – Excluding brokered deposit growth 0.5% growth NPAs / Assets Ratio 1.33% vs. 0.95% NPLs / Gross Loans Ratio 1.64% vs. 1.14% Reserves / NPLs Ratio 60.7% vs. 85.0%

Experienced Leadership Executive Title Years of Banking Experience Joined FCCB Randall E. Black Vice Chairman, President & CEO 32 1993 Stephen J. Guillaume Executive VP & CFO 16 2009 David Z. Richards Jr. Sr Executive VP & Board Director 48 2017 Jeffrey L. Wilson Sr Executive VP & Chief Credit Officer 38 1987 LeeAnn Gephart Executive VP & Chief Banking Officer 19 2021 Jeffrey R White Executive VP & COO 8 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

Citizens Financial Services, Inc. has continually been ranked one of the top 100 best performing community banks in the nation. 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 and PA. In 2022 FCCB was included in the ABA Nasdaq Community Bank Index – an indication of our progress and leadership capabilities in the market. FCCB maintains its "Bank On" Certification (awarded 2022), a national standard promoted by the CFE Fund, validating our commitment to providing safe, affordable, and accessible banking accounts for all. Recognized for our dedication to serving military families. FCCB is also a proud participant in the Veterans Benefits Banking Program (VBBP), ensuring safe and accessible banking for veterans. First Citizens Community Bank (FCCB) has been honored with the Federal Home Loan Bank of Pittsburgh's (FHLBank) 2025 Pillars of the Community Award. This is FHLBank's highest organizational honor 2025 and 2024: FCCB was recognized by Newsweek and Plant-A Insights Group as one of the top regional banks in the U.S. This distinction is based on a rigorous evaluation of profitability, financial relevance, risk exposure, and customer metrics. 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

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: 0.03% 0.00% 0.03% 0.11% 0.03% 0.01% Annualized

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 For the Twelve Months Ended, For the Quarter Ended, Dollars in thousands 12/31/2023 12/31/2024 12/31/2025 6/30/2025 9/30/2025 12/31/2025 3/31/2026 Total common equity $279,666 $299,734 $338,051 $313,653 $327,682 $338,051 $343,578 Total intangible assets 89,408 88,650 87,979 88,288 88,132 87,979 87,831 Tangible common equity $190,258 $211,084 $250,072 $225,365 $239,550 $250,072 $255,747 Total assets $2,975,321 $3,025,724 $3,064,564 $2,967,274 $3,056,269 $3,064,564 $3,026,478 Total intangible assets 89,408 88,650 87,979 88,288 88,132 87,979 87,831 Tangible assets $2,885,913 $2,937,074 $2,976,585 $2,878,986 $2,968,137 $2,976,585 $2,938,647 Accumulated other comprehensive gain (loss) income ($24,911) ($23,521) ($12,377) ($21,026) ($14,650) ($12,377) ($14,682) TCE / TA 6.59% 7.19% 8.40% 7.83% 8.07% 8.40% 8.70% TCE / TA (Excl. AOCI) 7.46% 7.99% 8.82% 8.56% 8.56% 8.82% 9.20% Tangible Book Value Per Share $39.63 $43.91 $52.02 $46.88 $49.83 $52.02 $53.23

Non-GAAP Reconciliation