FIRST BUSEY CORP /NV/

This Annual Report contains certain financial information determined by methods other than in accordance with GAAP. Management uses these non-GAAP financial measures and non-GAAP ratios, together with the related GAAP financial 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.

Non-GAAP disclosures have inherent limitations and are not audited. They should not be considered in isolation or as a substitute for the 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 federal income tax rates or effective tax rates as noted with the tables below.

The following tables present reconciliations between these non-GAAP measures and what management believes to be the most directly comparable GAAP financial measures.

First Busey Corporation(BUSE) | 2025 —28

1. Beginning in 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.

First Busey Corporation(BUSE) | 2025 —29

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 Consolidated Statements 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 by using tax rates of 26.3%, 24.9%, and 20.4% for the years ended December 31, 2025, 2024, and 2023, respectively.

4. A deferred valuation tax adjustment in 2025 was recorded in connection with the CrossFirst acquisition. Additionally, 2025 includes a write-off of deferred tax assets related to non-deductible compensation and 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 Consolidated Statements 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.

First Busey Corporation(BUSE) | 2025 —30

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.

First Busey Corporation(BUSE) | 2025 —31

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 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.

First Busey Corporation(BUSE) | 2025 —32

1. Beginning in 2025, Busey revised its calculation of tangible assets and tangible common equity for all periods presented to exclude any tax adjustment.

First Busey Corporation(BUSE) | 2025 —33