Q4 2025 EARNINGS INVESTOR PRESENTATION January 27, 2026

24Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE This presentation may contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 with respect to First Busey Corporation’s (“Busey’s”) financial condition, results of operations, plans, objectives, future performance, and business. Forward-looking statements, which may be based upon beliefs, expectations and assumptions of Busey’s management and on information currently available to management, are generally identifiable by the use of words such as “believe,” “expect,” “anticipate,” “plan,” “intend,” “estimate,” “may,” “will,” “would,” “could,” “should,” “position,” or other similar expressions. Additionally, all statements in this document, including forward-looking statements, speak only as of the date they are made, and Busey undertakes no obligation to update any statement in light of new information or future events. A number of factors, many of which are beyond Busey’s ability to control or predict, could cause actual results to differ materially from those in any forward-looking statements. These factors include, among others, the following: (1) the strength of the local, state, national, and international economies and financial markets (including effects of inflationary pressures, the threat or implementation of tariffs, trade wars, and changes to immigration policy); (2) changes in, and the interpretation and prioritization of, local, state, and federal laws, regulations, and governmental policies (including those concerning Busey's general business); (3) the economic impact of any future terrorist threats or attacks, widespread disease or pandemics, military conflicts, acts of war or threats thereof, or other adverse external events that could cause economic deterioration or instability in credit markets (including Russia’s invasion of Ukraine, the conflicts in the Middle East, and recent military activity in Venezuela); (4) unexpected results of acquisitions, including the acquisition of CrossFirst, which may include the failure to realize the anticipated benefits of the acquisitions and the possibility that the transaction and integration costs may be greater than anticipated; (5) the imposition of tariffs or other governmental policies impacting the value of products produced by Busey's commercial borrowers; (6) new or revised accounting policies and practices as may be adopted by state and federal regulatory banking agencies, the Financial Accounting Standards Board, the Securities and Exchange Commission, or the Public Company Accounting Oversight Board; (7) changes in interest rates and prepayment rates of Busey’s assets (including the impact of sustained elevated interest rates); (8)  increased competition in the financial services sector (including from non-bank competitors such as credit unions, private credit, and fintech companies) and the inability to attract new customers; (9) technological changes implemented by us and other parties, including our third-party vendors, which may have unforeseen consequences to us and our customers, including the development and implementation of tools incorporating artificial intelligence; (10) the loss of key executives or associates, talent shortages, and employee turnover; (11) unexpected outcomes and costs of existing or new litigation, investigations, or other legal proceedings, inquiries, and regulatory actions involving Busey (including with respect to Busey’s Illinois franchise taxes); (12)  fluctuations in the value of securities held in Busey’s securities portfolio, including as a result of changes in interest rates; (13)  credit risk and risk from concentrations (by type of borrower, geographic area, collateral, and industry), within Busey's loan portfolio and large loans to certain borrowers (including commercial real estate loans); (14)  the concentration of large deposits from certain clients who have balances above current Federal Deposit Insurance Corporation insurance limits and may withdraw deposits to diversify their exposure; (15) the level of non-performing assets on Busey’s balance sheets; (16)  interruptions involving information technology and communications systems or third-party servicers; (17)  breaches or failures of information security controls or cybersecurity-related incidents; (18)  the economic impact on Busey and its customers of climate change, natural disasters, and exceptional weather occurrences such as tornadoes, hurricanes, floods, blizzards, and droughts; (19) the ability to successfully manage liquidity risk, which may increase dependence on non-core funding sources such as brokered deposits, and may negatively impact Busey's cost of funds; (20) the ability to maintain an adequate level of allowance for credit losses on loans; (21) the effectiveness of Busey’s risk management framework; and (22) the ability of Busey to manage the risks associated with the foregoing. These risks and uncertainties should be considered in evaluating forward-looking statements and undue reliance should not be placed on such statements. Additional information concerning Busey and its business, including additional factors that could materially affect Busey’s financial results, is included in Busey’s filings with the Securities and Exchange Commission. Forward-Looking Statements

34Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Table of Contents Overview of First Busey Corporation (BUSE) 4 4Q25 Review 5 Investment Highlights 6 Earnings Performance 7 Attractive Markets Positioned for Growth 8 Strategically Configured Regional Operating Model 9 High Quality Loan Portfolio 10 Well-Diversified & Conservatively Underwritten Portfolio 11 Pristine Credit Quality 12 Top Tier Core Deposit Franchise 13 Net Interest Margin 14 Diversified and Significant Sources of Noninterest Income 15 Wealth Management 16 Focused Control on Expenses 17 Robust Capital Foundation 18 Appendix: 19 Seasoned Leadership Team 20 Purchase Accounting Projections 21 Non-GAAP Financial Information 22

44Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Overview of First Busey Corporation (NASDAQ: BUSE) Holding company of a 158+ year old bank Corporate headquarters in Leawood, KS ▪ Treasury Management Services and Payment Technology Solutions $18.1 Billion Total Assets $15.7 Billion Wealth Assets Under Care $2.2 Billion Market Cap 1 ▪ Premier Commercial Banking Franchise with attractive market footprint ▪ Full-service Trust Company 1 Market cap as of 1/26/26 Powerful Combination of Banking, Wealth, and Payments Business Lines Sizable business lines that provide a full suite of solutions to our clients at every stage of their business and personal life

54Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE 1 Non-GAAP calculations, see Appendix | 2 4Q25 adjusted noninterest expense was elevated due to a $3.8 million operating loss tied to one relationship 4Q25 Review Financial Results (Non-GAAP) Metric 1 3Q25 4Q25 Adj. Diluted EPS $0.64 $0.68 Adj. Net Income to Common S/H $57 million $61 million Total Operating Revenue $197 million $201 million Net Interest Margin 3.58% 3.71% Net Interest Income $155 million $158 million Adj. Noninterest Income $42 million $43 million Adj. Pre-Provision Net Revenue $84 million $85 million Adj. PPNR ROAA 1.78% 1.85% Adj. ROAA 1.33% 1.41% Adj. ROATCE 13.20% 13.58% Adj. Efficiency Ratio 54.8% 55.0% Total Assets $18.2 billion $18.1 billion Total Loans $13.6 billion $13.6 billion Total Deposits $15.1 billion $14.9 billion TBV / Share $19.69 $20.23 ▪ NIM up +13 bps QoQ and up +76 bps YoY as a result of balance sheet optimization strategies alongside higher loan repricing and strong deposit cost control Net Interest Margin sustains upward trajectory ▪ Assets Under Care of $15.7 billion at 12/31/25, up $1.8 billion YoY, as strong net AUC inflows across our footprint combined with market lift to compound AUC growth ▪ 4Q25 Wealth segment revenue of $18.3 million was a new quarterly record and $70.2 million of Wealth segment revenue for FY 2025 was the highest in company history Wealth management exhibits excellent performance ▪ TBV per share up $2.35/share, or +13%, since 12/31/24; TBV per share plus dividend up 19% ▪ During 4Q25, returned $30 million to shareholders via share repurchases (1.25 million shares at a weighted average price of $23.84 per share), for a FY 2025 total of $70 million and ~3.5% of outstanding shares (3.06 million shares at a weighted average price of $22.81 per share) Tangible Book Value continues to compound as Share Repurchase Plan remains active ▪ $680 million in 4Q25 new loan production was +$273 million higher than 3Q25, but payoffs tempered net balances a decline of $30 million QoQ ▪ Deposit decline of $164 million was due to intentional runoff of $55 million of brokered and $125 million of corporate deposits from our targeted runoff of high-cost non-relationship deposits. Excluding these intentional optimization actions, operating deposits are up +$16 million QoQ. Additionally, experienced normal seasonal public fund outflows of ~$240 million that are expected to rebuild in 2Q26 and 3Q26, consistent with prior years Loans and deposits experience a modest contraction ▪ Profitability accelerated to a 1.41% adj. ROAA1 and 55.0% adj. efficiency ratio1 in 4Q25, compared to 1.02% adj. ROAA1 and 61.8% adj. efficiency ratio1 in 4Q24 Accelerating Profitability $157.6 $43.4 -$111.1 -$4.4 -$2.4 -$16.7 -$1.1 -$4.6 $60.6 Net Interest Income Adj. Noninterest Income¹ Adj. Noninterest Expense¹ Amort. of Intangibles Provision for credit losses Income taxes Reversal of tax benefit from non- operating costs Preferred Dividend Net Income to Common¹ 4Q25 Summary Income Statement 21.6% Effective Tax Rate after YTD true-up +1.6% QoQ+4.4% QoQ Includes an Op. Loss2 1.28% Allowance/ Loans $ in millions

64Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Attractive Profitability and Returns Disciplined Growth Strategy Driven by Regional Operating Model Balance Sheet Strength 1 Non-GAAP calculation, see Appendix | 2 On- and off-balance sheet liquidity is comprised of cash and cash equivalents, debt securities excluding those pledged as collateral, brokered deposits, and Busey’s borrowing capacity through its revolving credit facility, the FHLB, the Federal Reserve Bank, and federal funds purchased lines | 3 4Q25 capital ratios are preliminary estimates | 4 Most recent quarter reported for KRX components as of 1/26/26 | 5 Market Data for BUSE updated to close on 1/26/26 | 6 Based on consensus median net income of covering analysts as of 1/26/26 Investment Highlights ▪ Long history of quality earnings performance ▪ Substantial improvements in ROAA1, ROATCE1, Net Interest Margin1, and Efficiency Ratio1 in 2025 as synergy realization ramped from recently integrated acquisition ▪ Quarterly common stock dividend of $0.26 (4.2% yield)5, increased by $0.01, or +4%, in Jan. 2026 ▪ Active share repurchase program with $70 million, or ~3% of outstanding shares, repurchased during 2025 ▪ Organic growth powered by an approach that brings the full capabilities of commercial, wealth, and payments to each community through local leadership and autonomy ▪ Anticipated primary organic growth drivers are expansion in new high-growth markets, successful hiring/retaining of top-tier talent, and delivering the full suite of solutions to the entirety of the client base ▪ Efficient branch network — average deposits per branch of $189 million at 12/31/25 ▪ Executed nine strategic acquisitions over the last decade to enhance franchise value without unduly diluting shareholders, including the TBV-accretive acquisition of $7.5 billion asset CrossFirst Bank in 2025 ▪ High quality, commercially-oriented loan portfolio is well-diversified by sector and geographic location and conservatively underwritten with low levels of concentration; strong reserve levels with ACL/Loans at 1.28% ▪ Stable, low-cost core deposit franchise: 93.7% core deposits1, 24.6% of total deposits were noninterest-bearing, 1.91% total cost of deposits in 4Q25, 1.80% total deposit spot cost at 12/31/25 ▪ Resilient liquidity profile with available sources of on- and off-balance sheet liquidity2 totaling $7.7 billion, including $0.3 billion of cash and cash equivalents ▪ Robust capital foundation with capital ratios at $830 million+ excess over well-capitalized minimums with capital buffer: TCE/TA of 10.1%, CET1 of 12.4%, and Total Capital of 15.9% at 12/31/253 $ in billions FY 2024 4Q25 Metrics better than KRX median in bold KRX Median MRQ 4 Total Assets $12.0 $18.1 $31.8 Total Loans $7.7 $13.6 $21.9 Total Deposits $10.0 $14.9 $25.6 Total Wealth AUC $13.8 $15.7 NM TCE Ratio1 8.7 % 10.1 % 8.8 % CET1 Ratio3 14.1 % 12.4 % 12.1 % NPA/Assets 0.19 % 0.32 % 0.41 % Net Interest Margin 1 2.95 % 3.71 % 3.57 % Adj. Nonint. Income % of Operating Revenue 1 30.0 % 21.6 % 17.4 % Adj. PPNR ROAA 1 1.39 % 1.85 % 1.79 % Adj. ROAA 1 1.00 % 1.41 % 1.36 % Adj. ROATCE 1 12.3 % 13.6 % 15.3 % Adj. Efficiency Ratio 1 61.3 % 55.0 % 54.7 % Market Cap 5 $2.2 $4.5 Dividend Yield 5 4.2% 2.9 % Price / TBV 5 1.2x 1.7x Price / 2026E 6 9.7x 10.7x Financial Highlights

74Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE $12.33 $30.88 FY 2015 FY 2016 FY 2017 FY 2018 FY 2019 FY 2020 FY 2021 FY 2022 FY 2023 FY 2024 FY 2025 $10 $20 $30 $30.9 $39.9 $57.2 $57.4 $60.6 $0.53 $0.57 $0.63 $0.64 $0.68 Adj. Net Income Avail. to Common S/H Adj. EPS 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 11.9% 10.6% 13.6% 13.2% 13.6% 1.02% 1.09% 1.21% 1.33% 1.41% Adj. ROATCE Adj. ROAA 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 1 Non-GAAP calculation, see Appendix | 2 Includes cumulative dividends per share over the period | 3 Market Data for BUSE updated to close on 1/26/26 Earnings Performance Adjusted Net Income & Earnings Per Common Share 1 Adjusted ROATCE & Adjusted ROAA 1 $ in millions $0.38 $0.68 2015 Q4 2016 Q4 2017 Q4 2018 Q4 2019 Q4 2020 Q4 2021 Q4 2022 Q4 2023 Q4 2024 Q4 2025 Q4 $0.25 $0.50 $0.75 Earnings Track Record: Adj. EPS 10-Year Trend +9.62% CAGR +$18.55 Current common stock dividend yield of 4.2%3 Tangible Common BV 1 / Share (ex-AOCI) + Dividends 2

84Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Attractive Markets Positioned for Growth 1 Market Nominal GDP as of 2023 per FRED, Federal Reserve Bank of St. Louis | Source: S&P Capital IQ Pro; Census.gov; BEA.gov | Note: Chart does not include markets with populations under 500,000 people 1

94Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Strategically Configured Regional Operating Model Focused on bringing the full breadth of commercial, wealth, and payments to provide a broad set of financial solutions to well-capitalized individuals and the companies they own & operate Life Equity Lending Sponsor Finance Energy Lending SBA Lending $5B deposits $5B deposits $3B loans $12B AUC $4B AUC $4B loans $3B deposits $2B loans $1B deposits $1B loans $1B deposits $2B loans $1.5B loans Enterprise-wide sales structure is organized by region – bringing full capabilities and the complete Busey experience to each community through local leadership and autonomy Note: Balances based on origination location and rounded to nearest billion dollars; data as of 12/31/25

104Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Commercial & Industrial 31% Owner- Occupied CRE 11%Non-Owner- Occupied CRE 30% Real Estate Construction 8% Residential Real Estate 16% Other 4% 1 Capital is Busey Bank Tier 1 Capital (preliminary estimates) + Allowance for credit losses | 2 Based on loan origination | 3 Includes $5.8 million of net charge-offs, which represent an immaterial percentage of other payoffs Classified Assets / Capital 1 NPLs / Total Loans 7.5% 0.39% High Quality Loan Portfolio Loan Portfolio Regional Segmentation 2 Loan Portfolio Composition Total Loan Portfolio: $13.6 Billion Commercially-oriented portfolio is well-diversified by sector and geographic location and conservatively underwritten with low levels of concentration Portfolio 2025 Q3 QoQ ∆ 2025 Q4 % of Total East (Chicago, St. Louis, SW FL) $3,941 +$29 $3,970 29.3 % Midwest (Central IL, Indy) $3,254 +$17 $3,271 24.1 % Central (KC, Wichita, OKC, Tulsa) $1,904 +$119 $2,023 14.9 % Texas (Dallas, Fort Worth) $1,958 -$172 $1,786 13.2 % West (AZ, CO, NM) $987 +$21 $1,008 7.4 % Verticals $1,555 -$45 $1,510 11.1 % Total Loans $13,599 -$30 $13,568 100 % Texas region was pressured by a few substantial planned CRE payoffs that were taken out on the now active secondary market, as well as ~$35 million of PCD loan payoffs Central region grew loans by ~5% QoQ; driven by production in Kansas City and Oklahoma City $ in thousands 7.12% 6.91% 7.13% 7.06% 6.35% 5.47% 5.76% 6.22% 6.20% 6.10% 4.53% 4.33% 4.32% 4.31% 3.79% Net New Funding Yield Loan Yield SOFR 30D 12/31/24 3/31/25 6/30/25 9/30/25 12/31/25 Loan Yield While maintaining focus on our guiding principles of pristine asset quality +$680 +$186 -$54 -$595 -$248 New Loan Production Net Line of Credit Draws PCD Loan Payoffs Other Payoffs³ Amortization $0 +$500 +$1,000 Commercial Loans / Total Portfolio 80% 100/300 Test 45% C&D / 225% CRE 4Q25 Loan Balances Change Life Equity Lending continued to provide loan production to partially offset declines in other verticals during 4Q25 Disciplined loan pricing remains a key enterprise-wide priority 4Q25 new production up by +$273 million compared to 3Q25, but net balance change tempered by payoffs $ in millions As of 12/31/25

114Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE 1 Investor owned CRE (CRE-I) includes C&D, Multifamily and non-owner occupied CRE | 2 Debt Service Coverage Ratio | 3 Net Operating Income of property divided by Loan Amount Note: Minor difference in balances from above charts and consolidated balances reported elsewhere is attributable to purchase accounting, deferred fees & costs, and overdrafts $ in millions Property Type 12/31/25 Balances % of Total Loans 12/31/25 Classified Balances Apartments $1,117.0 8.2 % $0.0 Industrial/Warehouse 891.7 6.6 % 0.1 Retail 773.6 5.7 % 5.1 Traditional Office 500.2 3.7 % 0.5 Land Acq. & Dev. 384.4 2.8 % 11.9 Hotel 339.0 2.5 % 0.0 Student Housing 267.3 2.0 % 0.0 Specialty 251.3 1.9 % 0.0 Self-Storage 149.6 1.1 % 0.0 Senior Housing 144.2 1.1 % 0.0 Medical Office 135.5 1.0 % 0.0 Other 215.5 1.6 % 0.0 Grand Total $5,169.3 38.2 % $17.6 $ in millions Property Type 12/31/25 Balances % of Total Loans 12/31/25 Classified Balances Industrial/Warehouse $487.9 3.6 % $11.6 Specialty 338.6 2.5 % 6.3 Traditional Office 211.2 1.6 % 1.3 Medical Office 151.4 1.1 % 0.0 Retail 122.9 0.9 % 1.5 Restaurant 115.4 0.9 % 7.7 Other 18.1 0.1 % 3.7 Grand Total $1,445.5 10.7 % $32.1 Well-Diversified & Conservatively Underwritten Portfolio In ve st or -O w ne d C RE 1 All data as of 12/31/25 $ in millions Investor Owned CRE Metric Traditional Office Medical Office Top 10 Largest Office Loans Total Balances $500.2 $135.5 $179.6 % of Total CRE-I 9.7 % 2.6 % 3.5 % % of Total Office CRE-I 78.7 % 21.3 % 28.3 % # of Loans 219 81 10 Average Loan Size $2.3 $1.7 $18.0 Total Classified $0.5 $0.0 $0.0 Weighted Avg Current LTV 60 % 63 % 62% Weighted Average DSCR2: Weighted Average Debt Yield3: Top Ten Largest Office Loans 1.41x 13.2% Only 0.3% of total CRE-I loans are classified 100/300 Test: 45% C&D 225% CRE-I Only 2.2% of total OOCRE loans are classified C&I lines of credits have an overall utilization of 50%, demonstrating substantial borrowing capacity and appropriate revolving of most lines Lower risk profiles as underwritten to the primary occupying business and are not as exposed to lease turnover risks $ in millions NAICS Sector 12/31/25 Balances % of Total Loans 12/31/25 Classified Balances Finance and Insurance $814.1 6.0 % $0.0 Manufacturing 490.0 3.6 % 38.0 Real Estate, Rental and Leasing 367.2 2.7 % 4.9 Food Services, Drinking Places 336.1 2.5 % 0.7 Construction 282.4 2.1 % 3.5 Mining, Quarrying, Oil, Gas 241.8 1.8 % 0.0 Wholesale Trade 208.7 1.5 % 7.8 Other Services (ex. Public Admin) 205.2 1.5 % 2.2 Transportation 195.4 1.4 % 8.1 Retail Trade 185.4 1.4 % 4.4 Agriculture, Forestry, Fishing 175.1 1.3 % 3.4 Health Care and Social Assist. 153.7 1.1 % 5.8 Professional, Scientific, Tech 129.9 1.0 % 17.0 Educational Services 114.8 0.8 % 0.1 Other 302.9 2.2 % 14.1 Grand Total $4,202.7 30.9 % $110.0 O w ne r-O cc up ie d C RE C om m er ci al & In du st ria l ( C &I ) Majority of the Finance & Insurance portfolio (represents 19% of C&I loans, or 6% of total loans) is secured by marketable securities

124Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE ▪ Conservative underwriting and strong portfolio management has resulted in a continued legacy of pristine credit quality ▪ Processes in place that identify any early warning indicators and proactively engage the special assets group early in the credit review process (special assets group has remained intact since the 2008-2009 recession) ▪ Loans 90+ days past due and still accruing at $2.3 million, or 0.02% of total loans, and loans 30-89 days past due represent 0.12% of total loans ▪ Classified assets as a percentage of capital of 7.5%1 at 12/31/25, compared to KRX median of 12.0% as of 9/30/25 ▪ OREO and repossessed asset balances total $4.6 million at 12/31/25, down from $10.2 million at 9/30/25 due to successful disposition of certain assets ▪ 4Q25 net credit provision expense of $2.4 million; FY 2025 net operating provision expense totaled $3.1 million 1 Capital calculated as Busey Bank Tier 1 Capital (preliminary estimates) + Allowance for credit losses 2Average loans was calculated as the average of the ending portfolio loan balances over the most recent four quarters Pristine Credit Quality Nonperforming Assets / Total Assets Net Charge-Offs / Average Loans (Annualized) 2 0.13% 0.06% 0.19% 0.32% 0.32% 0.23% 0.31% 0.46% 0.40% Busey KRX Median 2022 YE 2023 YE 2024 YE 2025 Q3 2025 Q4 $ in millions $ in millions BUSE NPAs $16.6 $7.9 $23.3 $57.7 $58.1 BUSE NCOs $0.9 $2.3 $18.2 $5.8 $5.8 0.01% 0.03% 0.23% 0.17% 0.17% 0.05% 0.16% 0.19% 0.18% Busey KRX Median 2022 YE 2023 YE 2024 YE 2025 Q3 2025 Q4 ▪ Reserves + purchase accounting marks / loans = 1.92% ▪ Allowance to Nonperforming Loans coverage of 3.25 x Allowance / Loans 1.19% 1.20% 1.08% 1.28% 1.28% 1.07% 1.17% 1.17% 1.17% Busey KRX Median 2022 YE 2023 YE 2024 YE 2025 Q3 2025 Q4

134Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE East & Midwest regions were impacted by outflows of seasonal public funds totaling ~$240 million that are expected to rebuild in 2Q26 and 3Q26, consistent with prior years Noninterest- bearing 25% Interest-bearing 21% Savings & Money Market 38% Time <250k 10% Time >250k 6% 1 Non-GAAP calculation, see Appendix Loan to Deposit Ratio 91.0% Core Deposits 1 93.7% MRQ Avg Cost of Total Deposits 1.91% Top Tier Core Deposit Franchise Deposit Portfolio Composition Total Deposits: $14.9 Billion Deposit Portfolio Regional Segmentation Portfolio 2025 Q3 QoQ ∆ 2025 Q4 % of Total East (Chicago, St. Louis, SW FL) $4,946 -$19 $4,927 33.1 % Midwest (Central IL, Indy) $5,314 +$35 $5,349 35.9 % Central (KC, Wichita, OKC, Tulsa) $3,075 -$121 $2,954 19.8 % Texas (Dallas, Fort Worth) $697 +$24 $721 4.8 % West (AZ, CO, NM) $815 -$18 $797 5.3 % Verticals $223 -$65 $158 1.1 % Total Deposits $15,070 -$164 $14,906 100 % $ in thousands Central region deposit outflows attributed to intentional deposit runoff of $55 million in brokered and $125 million of corporate deposits from the targeted runoff of high-cost non-relationship deposits 1.75% 1.91% 2.21% 2.15% 1.91% 2.19% 2.00% 2.00% 1.99% Busey KRX Median 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 1.00% 1.50% 2.00% 2.50% 3.00% Successful Post-Acquisition Deposit Optimization Strategy: Total Cost of Deposits vs. Peers Spot Deposit Costs At 9/30/25 At 12/31/25 Change Total Deposits 2.01% 1.80% -21 bps Non-Time Deposits 1.69% 1.44% -25 bps 53% deposit beta during 4Q25 63% deposit beta during 2H25 3/1/25: Closed acquisition of CrossFirst Bankshares 6/28/25: Merged CrossFirst Bank into Busey Bank 38% of total deposits are priced at 1 basis point or less Average Deposits per Branch $189 million As of 12/31/25

144Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE $81.6 $103.7 $153.2 $155.1 $157.6 $80.8 $101.0 $146.1 $149.2 $152.4$0.8 $2.7 $7.1 $5.9 $5.2 Net Interest Income Purchase Accounting Accretion 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 4.75% 5.08% 5.63% 5.63% 5.53% 1.89% 2.02% 2.29% 2.22% 1.97% 2.95% 3.16% 3.49% 3.58% 3.71% Earning Assets Cost of Funds NIM 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 1 Tax-equivalent adjusted amounts; Non-GAAP, see Appendix 2 Based on a static balance sheet that is projected over one- and two-year time horizons, with net interest income calculated under current market rates assuming permanent instantaneous shifts $ in millions Factors contributing to the QoQ +13 bps NIM expansion and Net Interest Income increase of +$2.4 million Net Interest Margin Trend 1Net Interest Income Trend Net Interest Margin Note: Company Purchase Accounting Schedule in appendix Avg IE Assets ($B) $11.05 $13.36 $17.70 $17.27 $16.94 2026 2027 2028 Roll-off Cash Flow ($ millions) $347 $290 $316 Approximate Roll-off Yield 2.9 % 3.0 % 3.0 % 2026 2027 2028 Balances ($ millions) $1,068 $985 $720 Weighted Average Rate 4.7 % 4.8 % 5.4 % Scheduled Maturities / Repricing of Fixed Rate Loans Roll-off of Securities ▪ Continued to benefit from the substantial amount of low-yield loans and securities rolling off into higher-yield products 4Q25 Net New Loan Funding Yield: 6.35% New Securities purchased at: ~4.50% Net Interest Income Rate Sensitivity 2 Rate Shock Year 1 NII Impact Year 2 NII Impact +200  bps +4.1 % +5.7 % +100  bps +2.3 % +3.1 % -100  bps -1.8 % -3.3 % -200  bps -2.2 % -5.6 % Balance sheet remains well- positioned for rate neutrality ▪ Reduced deposit costs by 24 bps QoQ (53% quarterly beta) by applying measured rate cutting initiatives to optimize funding costs ▪ Supplemented by the culminating stage of the post-acquisition balance sheet optimization strategy that targeted runoff of brokered and high-cost non-relationship funding: 4Q25 runoff totaled $180 million at a weighted-average rate of 4.2%

154Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Minimal contribution from other service charges such as NSF, overdraft, and consumer deposit fees Payment Technology Solutions is the consolidated revenue from FirsTech, which includes lockbox/ACH payment processing, merchant services, online payments, and other electronic payments Treasury Management Services includes commercial cash management services, wires, and other commercial business service charges 1 4Q25 adjusted noninterest income contributed 21.6% of total operating revenue (excludes net securities gains) | 266.9% of 4Q25 adjusted noninterest income is contributed by wealth management fees, wealth management referral income included in other noninterest income, payment technology solutions revenue, and revenue lines managed by treasury management division (treasury management services revenue and corporate credit card interchange) | 3 Non-GAAP calculation, see Appendix | 4 Approximately $0.2 million of Other Noninterest Income was attributable to the wealth segment in 4Q24 and 4Q25 $117.0 $140.7 $192.0 $196.7 $200.9 $35.4 $37.0 $38.9 $41.5 $43.4 $81.6 $103.7 $153.2 $155.1 $157.6 30.3% 26.3% 20.2% 21.1% 21.6% Adj. Nonint. Inc. Net Interest Income Adj. Nonint. Inc./Op. Rev. 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 $ in millions Noninterest Income Detail 2024 Q4 YoY Change 2025 Q4 % of Total (Adj.) Wealth Management Fees $16,786 +8 % $18,101 41.7 % Payment Technology Solutions 5,094 -4 % 4,879 11.3 % Treasury Management Services 2,130 +122 % 4,726 10.9 % Card Services and ATM Fees 3,477 +34 % 4,660 10.7 % Other Service Charges on Deposit Accounts 2,381 -32 % 1,618 3.7 % Mortgage Revenue 496 +62 % 803 1.9 % Income on Bank Owned Life Insurance 1,080 +65 % 1,783 4.1 % Other Noninterest Income4 3,973 +71 % 6,788 15.7 % Adjusted Noninterest Income $35,417 +22 % $43,358 100 % Net Securities Gains (Losses) (196) (667) Total Noninterest Income $35,221 +21 % $42,691 $ in thousands Adjusted Noninterest Income / Operating Revenue 3 Sources of Noninterest Income Diversified and Significant Sources of Noninterest Income Capital Markets activities drove growth momentum for Other Noninterest Income in 4Q25 (YoY growth of ~$2.6mm in swap, letter of credit, and syndication fees) 21.6% 66.9% Wealth + Payment Tech + Treasury Management / Total Noninterest Income 2 Adjusted Noninterest Income / Total Revenue 1 4Q25 includes $1.1 million of interchange from corporate credit cards that are managed within the Treasury Management division Net interest income became a larger share of total operating revenue with significant NIM expansion and recent acquisition

164Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE $17.0 $17.6 $17.0 $17.4 $18.3 $7.7 $8.2 $7.7 $7.5 $8.5 45.4% 46.6% 45.1% 43.0% 46.6% Revenue Pre-Tax Net Income Pre-Tax Profit Margin 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 $13,834 $13,678 $14,102 $14,959 $15,657 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 ▪ Assets Under Care (AUC) up $0.7 billion QoQ and up $1.8 billion YoY, or +13% ▪ Strong net AUC inflows combined with market lift continue to compound AUC growth 1 Wealth Management segment 2 Busey Wealth Management’s blended portfolio 3-year and 5-year returns vs. blended benchmark of 60% MSCI All-Country World Index and 40% Bloomberg Intermediate Govt/Credit Index $ in millions $ in millions Wealth Management Wealth Revenue Composition 1 % of Total WM Revenue 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 Trust / Agency 84 % 81 % 83 % 86 % 86 % Brokerage 8 % 8 % 8 % 8 % 8 % Ag Services 2 % 9 % 2 % 1 % 2 % Tax & Financial Planning 1 % 0 % 4 % 1 % 1 % Estate Settlement 4 % 1 % 2 % 3 % 2 % Other 1 % 1 % 1 % 1 % 1 % Total 100 % 100 % 100 % 100 % 100 % $15.7 Billion Assets Under Care FY 2025 Revenue1$70.2 Million ▪ New Managing Directors in Kansas City, Wichita, Oklahoma City, Dallas and Denver that were hired in 2Q25 and 3Q25 have ramped production ▪ Early wins in Western markets - new accounts opened in 2025 representing ~$116 million of AUC, with another $95 million+ of AUC currently in later stages of the pipeline ▪ Track record of organic AUC growth in new markets: since 2014, 50%+ of AUC growth has been organic ▪ $70.2 million of Wealth revenue1 in 2025, the highest in company history ▪ 4Q25 Wealth revenue1 of $18.3 million, a YoY increase of +8% and a new record quarterly revenue at the company ▪ Pre-tax net income of $8.5 million, a YoY increase of +10% ▪ Pre-tax profit margin of 46.6% in 4Q25 and 45.3% over the last twelve months Wealth Revenue and Pre-Tax Income 1Assets Under Care Early wins in new Western markets Integrated comprehensive capabilities to serve Personal & Institutional Clients ▪ Fully internalized investment office that utilizes a tailored, tax-efficient approach for each client, producing long-term returns that continue to outperform benchmarks2

174Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE 1 Non-GAAP, see Appendix | Note: Certain totals above may not tie exactly due to rounding. Detail amounts can be found in Non-GAAP table within Appendix $78.6 $112.0 $127.8 $120.0 $120.3 61.8% 58.7% 55.3% 54.9% 55.0% Expenses ex-Acq. Acquisition & Restruct. Exp. Adj. Efficiency Ratio¹ 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 $ in millions Noninterest Exp. $78.6 $112.0 $127.8 $120.0 $120.3 Acquisition & Restruct. Exp. $3.6 $26.0 $16.6 $7.2 $4.8 NIE ex- Acquisition & Restructuring Expense 1 $75.0 $86.0 $111.2 $112.8 $115.5 Amort. of Intangibles $2.5 $3.1 $4.6 $4.5 $4.4 Adjusted NIE 1 $72.6 $82.9 $106.6 $108.3 $111.1 Noninterest Expense Focused Control on Expenses 2025 Q3 2025 Q4 Compensation & Benefits $68.5 $65.0 Data processing $9.3 $9.6 Occupancy & Equipment $10.1 $10.1 Professional fees $2.6 $3.4 Other NIE $17.9 $23.1 Adjusted NIE 1 $108.3 $111.1 Adjusted NIE Summary FY 2024 FY 2025 % Change Operating Revenue1 $460.7 $730.4 +59 % Adjusted NIE1 $283.3 $408.9 +44 % Positive Operating Leverage: +15 % ▪ Non-operating expenses during 4Q25 were comprised of $4.8 million related to the CrossFirst acquisition ▪ Adjusted core NIE increased $2.8 million, primarily due to Other NIE ▪ Other NIE includes a $3.8 million operating loss tied to one relationship Synergies from the transformational CrossFirst acquisition produced strongly positive operating leverage for FY 2025 ▪ The anticipated cost savings from the CrossFirst acquisition (primarily personnel) were realized but were partially offset by new opportunistic hires ▪ 100% of the announced ~$25 million cost saves were out of the expense run rate by 12/31/25 ▪ Forthcoming upside for returns on recent people investments as newer hires build their books of business

184Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE 36% 39% 39% 39% 48% 77% 63% 93% Dividend Payout Ratio Payout Ratio with Dividends & Share Repurchases 2025 Q1 2025 Q2 2025 Q3 2025 Q4 25% 50% 75% 100% $1,237 $1,872 $1,888 $1,908 $1,920 14.1% 12.0% 12.2% 12.3% 12.4% 7.0% Common Equity Tier 1 CET1 Ratio Min + Buffer Ratio 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 $1,017 $1,676 $1,709 $1,748 $1,773 8.7% 8.8% 9.3% 9.9% 10.1% TCE TCE Ratio 2024 Q4 2025 Q1 2025 Q2 2025 Q3 2025 Q4 Tangible Common Equity 1 1 Non-GAAP calculation, see Appendix | 2 4Q25 capital ratios are preliminary estimates. 3 Common dividends and share repurchases during period divided by adjusted net income available to common shareholders during period $ in millions Common Equity Tier 1 Ratio Tier 1 Capital Ratio Total Capital Ratio Capital Ratio 12.4 % 13.9 % 15.9 % Minimum Well Capitalized with Capital Buffer 7.0 % 8.5 % 10.5 % Amount of Capital $1,920 $2,143 $2,460 Well Capitalized Minimum with Buffer $1,081 $1,313 $1,621 Excess over Well Cap. Min. with Buffer $839 $830 $839 $ in millions $ in millions Robust Capital Foundation Common Equity Tier 1 2 Consolidated Capital as of 12/31/25 2Adjusted Common Stock Payout Ratio 3

204Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Seasoned Leadership Team Has served as Chairman & CEO of First Busey since 2007 and became Chairman of the Board effective July 2020. Offers 40 years of diverse financial services experience and extensive board involvement with a conservative operating philosophy and management style that focuses on Busey’s associates, customers, communities and shareholders. Van A. Dukeman Chairman, President & CEO, First Busey Corp. Chairman & CEO, Busey Bank Tony Hammond President, Busey Bank Joined Busey in 2008 and has nearly 30 years of financial and leadership experience. Oversees various areas at Busey and its subsidiaries, including human resources, corporate communications, executive administration, marketing, the overall Busey experience, enterprise and strategic projects, as well as consumer and digital banking. Prior to Busey, Amy worked for 10+ years with CliftonLarsonAllen LLP. Amy L. Randolph Chief Operating Officer Joined Busey in January 2020 with over 25 years of financial leadership experience, including a 16-year tenure with KeyCorp. Oversees various areas at Busey and its subsidiaries, including enterprise, operational and third-party risk management, compliance, fair and responsible banking, vendor management, model risk, business continuity and information security. Monica L. Bowe Chief Risk Officer Joined Busey in March 2025 with the CrossFirst Bankshares merger and oversees various areas at Busey and its subsidiaries, including all information technology and business services and systems, service support, enterprise lending services, enterprise deposits and payments, and facilities. Previously, Amy held multiple executive leadership roles with CrossFirst Bank, most recently serving as Chief Operating Officer. Amy J. Fauss Chief Information & Technology Officer Joined Busey in 2011 and has over 20 years of experience in the financial services industry. Chip oversees all aspects of credit administration at Busey Bank, including commercial and consumer credit, portfolio monitoring and special assets. Before being named Chief Credit Officer in 2025, he has held the roles of President of Credit and Bank Administration, Co-Chief Banking Officer, and Regional President for Commercial Banking. Chip Jorstad Chief Credit Officer Joined Busey in September 2025. Oversees various areas at Busey and its subsidiaries—including accounting and corporate reporting, financial planning and analysis, budgeting and forecasting, corporate insights, capital markets, treasury, specialty finance and community investments, corporate development and investor relations. Chris previously served as Chief Strategy Officer at First National Bank, the largest subsidiary of F.N.B. Corporation. Chris H.M. Chan Chief Financial Officer Joined Busey in December 2011 and has over 45 years of legal experience. He oversees all legal matters and leads Busey’s corporate governance efforts. Prior to joining Busey, he was a shareholder in the law firm of Meyer Capel. John J. Powers General Counsel 2025 Proxy Statement: Executive Compensation Performance Measures Weighting Short-term incentives Adjusted EPS 35% Asset Quality Ratio 25% Fee Revenue from Wealth, Payment Technology Solutions, and Treasury Management 20% Core Deposit Growth 10% Strategic Integration of CrossFirst 6% Regulatory Ratings 4% Total 100% Long-term incentives Adjusted ROATCE 50% Relative Total Shareholder Return vs. KRX components 50% Total 100% Executive compensation reinforces corporate priorities following the acquisition of CrossFirst and is aligned with driving long-term shareholder value Joined Busey in May 2025. Oversees Busey’s regional operating sales and revenue model which includes all commercial, wealth, treasury management, payments and specialty business units. Tony has two decades of commercial banking experience—including serving as Head of Commercial and Middle Market Banking at HTLF and senior leadership roles at Arizona Bank & Trust, Johnson Bank and BOK Financial—with a track record of consistently leading high-performing teams, growing market share and attracting top talent across the industry.

214Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Estimated accretion schedule of loan discounts based on anticipated contractual cash flows In addition to CrossFirst Bankshares acquisition completed 3/1/25, these projections include remaining purchase accounting impact from prior M&A transactions, including acquisition of Merchants & Manufacturers Bank Corporation completed on 4/1/24 Purchase Accounting Projections ($ in thousands) Actuals Accretion/Amortization Impact Item 1Q25 2Q25 3Q25 4Q25 1Q26 2Q26 3Q26 4Q26 Thereafter Loans Accretion 2,272 6,576 6,088 5,571 5,447 5,127 4,851 4,551 66,652 CD Accretion 659 921 135 -5 -8 -6 -7 -5 289 Borrowings Amortization -203 -378 -369 -366 -357 -358 -358 -359 -3,707 Net NII Impact 2,728 7,119 5,854 5,200 5,082 4,763 4,486 4,187 63,234 Core Deposit Intangible & Wealth Intangibles Amortization -3,083 -4,592 -4,507 -4,432 -4,287 -4,227 -4,147 -4,078 -80,710 Total Pre-Tax Income Impact -355 2,527 1,347 768 795 536 339 109 -17,476

224Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Non-GAAP Financial Information This presentation contains certain financial information determined by methods other than U.S. Generally Accepted Accounting Principles (“GAAP”). Management uses these non- GAAP measures, together with the related GAAP measures, in analysis of Busey’s performance and in making business decisions, as well as for comparison to Busey’s peers. Busey believes the adjusted measures are useful for investors and management to understand the effects of certain non-core and non-recurring items and provide additional perspective on Busey’s performance over time. Included in the Appendix are tables that present reconciliations between these non-GAAP measures and what management believes to be the most directly comparable GAAP financial measures. These non-GAAP disclosures have inherent limitations and are not audited. They should not be considered in isolation or as a substitute for operating results reported in accordance with GAAP, nor are they necessarily comparable to non-GAAP performance measures that may be presented by other companies. Tax effected numbers included in these non-GAAP disclosures are based on estimated statutory rates, estimated federal income tax rates, or effective tax rates, as noted with the tables below.

234Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE ___________________________________________ 1. Beginning in the second quarter of 2025, Busey revised its presentation, for all periods presented, to reclassify the provision for unfunded commitments so that it is now included within the provision for credit losses; therefore, it is no longer included within total noninterest expense. 2. For quarterly periods, measures are annualized. Non-GAAP Financial Information (Unaudited) Pre-Provision Net Revenue and Related Measures Three Months Ended Years Ended (dollars in thousands) December 31, 2025 September 30, 2025 December 31, 2024 December 31, 2025 December 31, 2024 Net interest income (GAAP) $ 157,558 $ 155,137 $ 81,578 $ 569,609 $ 322,611 Total noninterest income (GAAP) 42,691 41,198 35,221 149,975 139,682 Net security (gains) losses (GAAP) 667 288 196 10,726 6,102 Total noninterest expense (GAAP)1 (120,320) (120,018) (78,622) (480,201) (301,494) Pre-provision net revenue (Non-GAAP) [a] 80,596 76,605 38,373 250,109 166,901 Acquisition and restructuring (income) expenses, excluding initial provision expenses 4,816 7,251 3,585 54,693 8,140 Realized net (gains) losses on the sale of mortgage service rights — — — — (7,724) Adjusted pre-provision net revenue (Non-GAAP) [b] $ 85,412 $ 83,856 $ 41,958 $ 304,802 $ 167,317 Average total assets [c] $ 18,309,250 $ 18,662,449 $ 12,085,993 $ 17,729,887 $ 12,051,871 Pre-provision net revenue to average total assets (Non-GAAP)2 [a÷c] 1.75 % 1.63 % 1.26 % 1.41 % 1.38 % Adjusted pre-provision net revenue to average total assets (Non-GAAP)2 [b÷c] 1.85 % 1.78 % 1.38 % 1.72 % 1.39 %

244Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Non-GAAP Financial Information (Unaudited) Adjusted Net Income, Average Tangible Common Equity, and Related Ratios Three Months Ended Years Ended (dollars in thousands, except per share amounts) December 31, 2025 September 30, 2025 December 31, 2024 December 31, 2025 December 31, 2024 Net income (GAAP) [a] $ 60,750 $ 57,098 $ 28,105 $ 135,262 $ 113,691 Day 2 provision for credit losses1 — — — 45,572 — Adjustment of initial provision for unfunded commitments due to adoption of new model2 — — — 4,030 — Other acquisition (income) expenses 4,859 7,251 2,469 54,736 6,901 Restructuring expenses (43) — 1,116 (43) 1,239 Realized net (gains) losses on the sale of mortgage servicing rights — — — — (7,724) Net securities (gains) losses 667 288 196 10,726 6,102 Related tax (benefit) expense3 (1,047) (2,141) (1,014) (30,228) (1,622) Non-recurring deferred tax adjustment4 — — — 4,919 1,446 Adjusted net income (Non-GAAP)5 [b] 65,186 62,496 30,872 224,974 120,033 Preferred dividends [c] 4,590 5,131 — 9,876 — Adjusted net income available to common stockholders (Non-GAAP) [d] $ 60,596 $ 57,365 $ 30,872 $ 215,098 $ 120,033 Weighted average number of common shares outstanding, diluted (GAAP) [e] 89,655,632 90,218,382 57,934,812 85,133,626 57,543,001 Diluted earnings per common share (GAAP) [(a-c)÷e] $ 0.63 $ 0.58 $ 0.49 $ 1.47 $ 1.98 Adjusted diluted earnings per common share (Non-GAAP)5 [d÷f] $ 0.68 $ 0.64 $ 0.53 $ 2.53 $ 2.09 Average total assets [g] $ 18,309,250 $ 18,662,449 $ 12,085,993 $ 17,729,887 $ 12,051,871 Return on average assets (Non-GAAP)6 [a÷g] 1.32 % 1.21 % 0.93 % 0.76 % 0.94 % Adjusted return on average assets (Non-GAAP)5,6 [b÷g] 1.41 % 1.33 % 1.02 % 1.27 % 1.00 % Average common equity $ 2,253,609 $ 2,210,711 $ 1,396,939 $ 2,145,484 $ 1,342,424 Average goodwill and other intangible assets, net (483,640) (486,625) (367,400) (469,187) (366,601) Average tangible common equity (Non-GAAP) [h] $ 1,769,969 $ 1,724,086 $ 1,029,539 $ 1,676,297 $ 975,823 Return on average tangible common equity (Non-GAAP)6 [(a-c)÷h] 12.59 % 11.96 % 10.86 % 7.48 % 11.65 % Adjusted return on average tangible common equity (Non-GAAP)5,6 [d÷h] 13.58 % 13.20 % 11.93 % 12.83 % 12.30 % ___________________________________________ 1. The Day 2 provision represents the initial provision for credit losses recorded in connection with the CrossFirst acquisition to establish an allowance on non-PCD loans and unfunded commitments and is reflected within the provision for credit losses line on the Statement of Income. 2. In the second quarter of 2025, Busey recorded an adjustment to the initial provision for unfunded commitments for CrossFirst acquisition-date balances based on revised estimates resulting from implementation of a new Current Expected Credit Losses model 3. Tax benefits were calculated for the year-to-date periods using tax rates of 26.28% and 24.88% for the years ended December 31, 2025 and 2024, respectively. Tax benefits for the quarterly periods were calculated as the year-to-date tax amounts less the tax reported for previous quarters during the year. 4. A deferred valuation tax adjustment in 2025 was recorded in connection with the CrossFirst acquisition and the expansion of Busey’s footprint into new states. Additionally, 2025 includes a write-off of deferred tax assets related to non-deductible acquisition-related expenses. A deferred tax valuation adjustment in 2024 resulted from a change to Busey’s Illinois apportionment rate due to recently enacted regulations. Deferred tax adjustments are reflected within the income taxes line on the Statement of Income. 5. Beginning in 2025, Busey revised its calculation of adjusted net income for all periods presented to include, as applicable, adjustments for net securities gains and losses, realized net gains and losses on the sale of mortgage servicing rights, and one-time deferred tax valuation adjustments. In 2024, these adjusting items were previously presented as further adjustments to adjusted net income. 6. For quarterly periods, measures are annualized.

254Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Non-GAAP Financial Information (Unaudited) Tax-Equivalent Net Interest Income, Adjusted Net Interest Income, Net Interest Margin, and Adjusted Net Interest Margin Three Months Ended Years Ended (dollars in thousands) December 31, 2025 September 30, 2025 December 31, 2024 December 31, 2025 December 31, 2024 Net interest income (GAAP) $ 157,558 $ 155,137 $ 81,578 $ 569,609 $ 322,611 Tax-equivalent adjustment1 860 788 446 2,976 1,693 Tax-equivalent net interest income (Non-GAAP) [a] 158,418 155,925 82,024 572,585 324,304 Purchase accounting accretion related to business combinations (5,200) (5,854) (812) (20,901) (3,166) Adjusted net interest income (Non-GAAP) [b] $ 153,218 $ 150,071 $ 81,212 $ 551,684 $ 321,138 Average interest-earning assets (Non-GAAP) [c] $ 16,941,000 $ 17,272,362 $ 11,048,350 $ 16,331,740 $ 10,999,424 Net interest margin (Non-GAAP)2 [a÷c] 3.71 % 3.58 % 2.95 % 3.51 % 2.95 % Adjusted net interest margin (Non-GAAP)2 [b÷c] 3.59 % 3.45 % 2.92 % 3.38 % 2.92 % ___________________________________________ 1. Tax-equivalent adjustments were calculated using an estimated federal income tax rate of 21%, applied to non-taxable interest income on investments and loans. 2. For quarterly periods, measures are annualized.

264Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE Non-GAAP Financial Information (Unaudited) ___________________________________________ 1. Tax-equivalent adjustments were calculated using an estimated federal income tax rate of 21%, applied to non-taxable interest income on investments and loans. 2. Beginning in the second quarter of 2025, Busey revised its presentation, for all periods presented, to reclassify the provision for unfunded commitments so that it is now included within the provision for credit losses; therefore, it is no longer included within total noninterest expense. This change affects all measures and ratios derived from total noninterest expense. Adjusted Noninterest Income, Revenue Measures, Adjusted Noninterest Expense, and Efficiency Ratios Three Months Ended Years Ended (dollars in thousands) December 31, 2025 September 30, 2025 December 31, 2024 December 31, 2025 December 31, 2024 Net interest income (GAAP) [a] $ 157,558 $ 155,137 $ 81,578 $ 569,609 $ 322,611 Tax-equivalent adjustment1 860 788 446 2,976 1,693 Tax-equivalent net interest income (Non-GAAP) [b] 158,418 155,925 82,024 572,585 324,304 Total noninterest income (GAAP) 42,691 41,198 35,221 149,975 139,682 Net security (gains) losses 667 288 196 10,726 6,102 Noninterest income excluding net securities gains and losses (Non-GAAP) [c] 43,358 41,486 35,417 160,701 145,784 Acquisition and restructuring (gain) loss — 44 — 44 — Realized net (gains) losses on the sale of mortgage service rights — — — — (7,724) Adjusted noninterest income (Non-GAAP) [d] $ 43,358 $ 41,530 $ 35,417 $ 160,745 $ 138,060 Tax-equivalent revenue (Non-GAAP) [e = b+c] $ 201,776 $ 197,411 $ 117,441 $ 733,286 $ 470,088 Adjusted tax-equivalent revenue (Non-GAAP) [f = b+d] 201,776 197,455 117,441 733,330 462,364 Operating revenue (Non-GAAP) [g = a+d] 200,916 196,667 116,995 730,354 460,671 Adjusted noninterest income to operating revenue (Non-GAAP) [d÷g] 21.58 % 21.12 % 30.27 % 22.01 % 29.97 % Total noninterest expense (GAAP)2 $ 120,320 $ 120,018 $ 78,622 $ 480,201 $ 301,494 Amortization of intangible assets (4,432) (4,507) (2,471) (16,614) (10,057) Noninterest expense excluding amortization of intangible assets (Non-GAAP)2 [h] 115,888 115,511 76,151 463,587 291,437 Acquisition and restructuring (income) expenses, excluding initial provision expenses (4,816) (7,207) (3,585) (54,649) (8,140) Adjusted noninterest expense (Non-GAAP)2 [i] $ 111,072 $ 108,304 $ 72,566 $ 408,938 $ 283,297 Efficiency ratio (Non-GAAP)2 [h÷e] 57.43 % 58.51 % 64.84 % 63.22 % 62.00 % Adjusted efficiency ratio (Non-GAAP)2 [i÷f] 55.05 % 54.85 % 61.79 % 55.76 % 61.27 %

274Q25 Earnings Investor Presentation First Busey Corporation | Ticker: BUSE ___________________________________________ 1. Beginning in 2025, Busey revised its calculation of tangible assets and tangible common equity for all periods presented to exclude any tax adjustment. Non-GAAP Financial Information (Unaudited) Tangible Assets, Tangible Common Equity, and Related Measures and Ratio As of (dollars in thousands, except per share amounts) December 31, 2025 September 30, 2025 December 31, 2024 Total assets (GAAP) $ 18,104,736 $ 18,188,628 $ 12,046,722 Goodwill and other intangible assets, net (480,729) (485,203) (365,975) Tangible assets (Non-GAAP)1 [a] $ 17,624,007 $ 17,703,425 $ 11,680,747 Total stockholders' equity (GAAP) $ 2,468,982 $ 2,448,835 $ 1,383,269 Preferred stock and additional paid in capital on preferred stock (215,197) (215,197) — Common equity [b] $ 2,253,785 $ 2,233,638 $ 1,383,269 Goodwill and other intangible assets, net (480,729) (485,203) (365,975) Tangible common equity (Non-GAAP)1 [c] $ 1,773,056 $ 1,748,435 $ 1,017,294 Tangible common equity to tangible assets (Non-GAAP)1 [c÷a] 10.06 % 9.88 % 8.71 % Ending number of common shares outstanding (GAAP) [d] 87,624,430 88,789,043 56,895,981 Book value per common share (Non-GAAP) [b÷d] $ 25.72 $ 25.16 $ 24.31 Tangible book value per common share (Non-GAAP) [c÷d] $ 20.23 $ 19.69 $ 17.88 Core Deposits and Related Ratio As of (dollars in thousands) December 31, 2025 September 30, 2025 December 31, 2024 Total deposits (GAAP) [a] $ 14,905,958 $ 15,070,162 $ 9,982,490 Brokered deposits, excluding brokered time deposits of $250,000 or more (70,140) (125,432) (13,090) Time deposits of $250,000 or more (876,207) (807,378) (334,503) Core deposits (Non-GAAP) [b] $ 13,959,611 $ 14,137,352 $ 9,634,897 Core deposits to total deposits (Non-GAAP) [b÷a] 93.65 % 93.81 % 96.52 %