BASIS OF PRESENTATION (Policies)	6 Months Ended
Jun. 30, 2026
Accounting Policies [Abstract]
Basis of Presentation	BASIS OF PRESENTATION The accompanying unaudited consolidated financial statements include the accounts of Old National Bancorp and its wholly owned subsidiaries (hereinafter collectively referred to as “Old National”) and have been prepared in conformity with accounting principles generally accepted in the United States of America and prevailing practices within the banking industry. Such principles require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and the disclosures of contingent assets and liabilities at the date of the financial statements and amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of management, the consolidated financial statements contain all the normal and recurring adjustments necessary for a fair statement of the financial position of Old National as of June 30, 2026 and December 31, 2025, and the results of its operations for the three and six months ended June 30, 2026 and 2025. Interim results do not necessarily represent annual results. Certain information and disclosures normally included in notes to consolidated annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in this Quarterly Report on Form 10-Q pursuant to SEC rules and regulations. These financial statements should be read in conjunction with Old National’s Annual Report on Form 10-K for the year ended December 31, 2025. All intercompany transactions and balances have been eliminated.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Accounting Guidance Pending Adoption Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 220 – In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires public business entities to disclose specified information about certain costs and expenses in the notes to financial statements at each interim and annual reporting period. Specifically, public business entities will be required to disclose the amounts of (a) purchases of inventory; (b) employee compensation; (c) depreciation; (d) intangible asset amortization; and (e) depreciation, depletion, and amortization recognized as part of oil- and gas-producing activities (or other amounts of depletion expense) included in each relevant expense caption. Within the same tabular disclosure, an entity must disclose certain expense, gain, or loss amounts that are already required under current GAAP. Further, an entity must disclose a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively. In addition, an entity must disclose the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. The amendments in this ASU are effective for annual periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. Old National is currently evaluating the impact of adopting this guidance on the consolidated financial statements. FASB ASC 350 – In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. The ASU revises ASC 350-40 to clarify and modernize the accounting and disclosure requirements for software costs. The new update eliminates ASC 350-50, which previously addressed website development costs, and incorporated its relevant guidance into ASC 350-40. The ASU refines ASC 350-40, but it does not entirely integrate the accounting approach for internal-use software with that for externally sold software under ASC 985-20. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. Old National is currently evaluating the impact of adopting this guidance on the consolidated financial statements. FASB ASC 326 – In November 2025, the FASB issued ASU 2025-08, Financial Instruments - Credit Losses (Topic 326): Purchased Loans. The ASU revises Topic 326 to simplify and improve the accounting for acquired financial assets. The update expands the application of the gross-up approach to include purchased seasoned loans, eliminating the complexity and inconsistency created by having separate models for PCD and non-PCD assets. Under the new guidance, the initial allowance for credit losses is added to the amortized cost basis rather than recorded as a Day 1 provision expense. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting periods. Early adoption is permitted. Old National is currently evaluating the impact of adopting this guidance on the consolidated financial statements. FASB ASC 815 – In November 2025, the FASB issued ASU 2025-09, Derivatives and Hedging (Topic 815): Hedge Accounting Improvements. The ASU introduces clarifications to Topic 815 building on improvements from ASU 2017‑12, and addresses challenges arising from the global reference rate reform (i.e., the LIBOR transition). The new guidance aims to reduce complexity in applying hedge accounting to transactions tied to an entity’s risk management activities and promotes consistency in accounting for forecasted transactions, interest rate flexibility, and nonfinancial components. The update expands eligibility for hedge accounting by allowing groups of forecasted transactions with similar risk exposures, provides guidance for hedging interest payments on debt with selectable interest rate indexes, clarifies hedging of specified components of nonfinancial assets, and eases restrictions related to net written options and certain compound derivatives. It also resolves presentation mismatches for certain foreign currency hedging relationships. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting periods. Early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the consolidated financial statements.

BASIS OF PRESENTATION (Policies)

The accompanying unaudited consolidated financial statements include the accounts of Old National Bancorp and its wholly owned subsidiaries (hereinafter collectively referred to as “Old National”) and have been prepared in conformity with accounting principles generally accepted in the United States of America and prevailing practices within the banking industry. Such principles require management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and the disclosures of contingent assets and liabilities at the date of the financial statements and amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. In the opinion of management, the consolidated financial statements contain all the normal and recurring adjustments necessary for a fair statement of the financial position of Old National as of June 30, 2026 and December 31, 2025, and the results of its operations for the three and six months ended June 30, 2026 and 2025. Interim results do not necessarily represent annual results. Certain information and disclosures normally included in notes to consolidated annual financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in this Quarterly Report on Form 10-Q pursuant to SEC rules and regulations. These financial statements should be read in conjunction with Old National’s Annual Report on Form 10-K for the year ended December 31, 2025.

All intercompany transactions and balances have been eliminated.

Accounting Guidance Pending Adoption

Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 220 – In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires public business entities to disclose specified information about certain costs and expenses in the notes to financial statements at each interim and annual reporting period. Specifically, public business entities will be required to disclose the amounts of (a) purchases of inventory; (b) employee compensation; (c) depreciation; (d) intangible asset amortization; and (e) depreciation, depletion, and amortization recognized as part of oil- and gas-producing activities (or other amounts of depletion expense) included in each relevant expense caption. Within the same tabular disclosure, an entity must disclose certain expense, gain, or loss amounts that are already required under current GAAP. Further, an entity must disclose a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively. In addition, an entity must disclose the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. The amendments in this ASU are effective for annual periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. Old National is currently evaluating the impact of adopting this guidance on the consolidated financial statements.

FASB ASC 350 – In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. The ASU revises ASC 350-40 to clarify and modernize the accounting and disclosure requirements for software costs. The new update eliminates ASC 350-50, which previously addressed website development costs, and incorporated its relevant guidance into ASC 350-40. The ASU refines ASC 350-40, but it does not entirely integrate the accounting approach for internal-use software with that for externally sold software under ASC 985-20. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those annual reporting periods. Early adoption is permitted as of the beginning of an annual reporting period. Old National is currently evaluating the impact of adopting this guidance on the consolidated financial statements.

FASB ASC 326 – In November 2025, the FASB issued ASU 2025-08, Financial Instruments - Credit Losses (Topic 326): Purchased Loans. The ASU revises Topic 326 to simplify and improve the accounting for acquired financial assets. The update expands the application of the gross-up approach to include purchased seasoned loans, eliminating the complexity and inconsistency created by having separate models for PCD and non-PCD assets. Under the new guidance, the initial allowance for credit losses is added to the amortized cost basis rather than recorded as a Day 1 provision expense. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting

periods. Early adoption is permitted. Old National is currently evaluating the impact of adopting this guidance on the consolidated financial statements.

FASB ASC 815 – In November 2025, the FASB issued ASU 2025-09, Derivatives and Hedging (Topic 815): Hedge Accounting Improvements. The ASU introduces clarifications to Topic 815 building on improvements from ASU 2017‑12, and addresses challenges arising from the global reference rate reform (i.e., the LIBOR transition). The new guidance aims to reduce complexity in applying hedge accounting to transactions tied to an entity’s risk management activities and promotes consistency in accounting for forecasted transactions, interest rate flexibility, and nonfinancial components. The update expands eligibility for hedge accounting by allowing groups of forecasted transactions with similar risk exposures, provides guidance for hedging interest payments on debt with selectable interest rate indexes, clarifies hedging of specified components of nonfinancial assets, and eases restrictions related to net written options and certain compound derivatives. It also resolves presentation mismatches for certain foreign currency hedging relationships. The amendments in this update are effective for all entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting periods. Early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the consolidated financial statements.