Note 1 - General	3 Months Ended
Mar. 31, 2026
Notes to Financial Statements
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]	Note 1. General Basis of Presentation The accompanying unaudited consolidated financial statements of First National Corporation (the Company) and its subsidiary, First Bank (the Bank), have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and in accordance with guidance provided by the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by GAAP for annual year-end financial statements. All significant intercompany balances and transactions have been eliminated. In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments and reclassifications of a normal and recurring nature considered necessary to present fairly the financial positions at March 31, 2026 and December 31, 2025, the statements of income and comprehensive income for the three months ended March 31, 2026 and 2025, the cash flows for the three months ended March 31, 2026 and 2025, and the changes in shareholders’ equity for the three months ended March 31, 2026 and 2025. The statements should be read in conjunction with the consolidated financial statements and related notes included in the Annual Report on Form 10-K for the year ended December 31, 2025. Operating results for the three months ended March 31, 2026 are not necessarily indicative of the results that may be expected for the year ending December 31, 2026. Certain items in the prior period financial statements have been reclassified to conform to the current presentation. These reclassifications had no effect on prior year net income or shareholders' equity. Significant Accounting Policies and Estimates Application of the principles of GAAP and practices within the banking industry requires management to make estimates, assumptions, and judgements that affect the amounts reported in the financial statements and accompanying notes. These estimates, assumptions, and judgements are based on information available as of the date of the financial statements; accordingly, as this information changes, the financial statements may reflect different estimates, assumptions and judgements. Certain policies inherently rely more extensively on the use of estimates, assumptions, and judgements and as such may have a greater possibility of producing results that could be materially different than originally reported. Material estimates that are particularly susceptible to significant changes in the near term include estimates related to the determination of the allowance for credit losses on loans. The Company’s significant accounting policies followed in the preparation of the unaudited consolidated financial statements are disclosed in Note 1 of the audited financial statements and notes for the year ended December 31, 2025 and are contained in the Company’s 2025 Annual Report on Form 10-K. There have been no significant changes to the application of significant accounting policies since December 31, 2025 . Recent Accounting Pronouncements In November 2025, the Financial Accounting Standards Board (FASB) issued ASU 2025-08, “Financial Instruments—Credit Losses (Topic 326): Purchased Loans.” The amendments in this ASU expand the population of acquired financial assets accounted for using the gross-up approach. Acquired loans (excluding credit cards) are deemed purchased seasoned loans and accounted for using the gross-up approach upon acquisition if criteria established by the new guidance are met. This change aims to enhance comparability, consistency, and better reflect the economics of acquiring financial assets. This ASU is effective for annual reporting periods beginning after December 15, 2026, and for interim reporting periods within those annual reporting periods. Early adoption is permitted in an interim or annual reporting period in which financial statements have not yet been issued or made available for issuance. If an entity adopts this ASU in an interim reporting period, it should apply it as of the beginning of that interim reporting period or the beginning of the annual reporting period that includes that interim reporting period. The Company does not expect the adoption of ASU 2025-08 to have a material impact on its consolidated financial statements. Other accounting standards that have been issued by the FASB or other standards setting bodies are not currently expected to have a material effect on the Company's financial position, results of operations or cash flows.

The accompanying unaudited consolidated financial statements of First National Corporation (the Company) and its subsidiary, First Bank (the Bank), have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and in accordance with guidance provided by the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by GAAP for annual year-end financial statements. All significant intercompany balances and transactions have been eliminated. In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments and reclassifications of a normal and recurring nature considered necessary to present fairly the financial positions at March 31, 2026 and December 31, 2025, the statements of income and comprehensive income for the three months ended March 31, 2026 and 2025, the cash flows for the three months ended March 31, 2026 and 2025, and the changes in shareholders’ equity for the three months ended March 31, 2026 and 2025. The statements should be read in conjunction with the consolidated financial statements and related notes included in the Annual Report on Form 10-K for the year ended December 31, 2025. Operating results for the three months ended March 31, 2026 are not necessarily indicative of the results that may be expected for the year ending December 31, 2026. Certain items in the prior period financial statements have been reclassified to conform to the current presentation. These reclassifications had no effect on prior year net income or shareholders' equity.

Significant Accounting Policies and Estimates

Application of the principles of GAAP and practices within the banking industry requires management to make estimates, assumptions, and judgements that affect the amounts reported in the financial statements and accompanying notes. These estimates, assumptions, and judgements are based on information available as of the date of the financial statements; accordingly, as this information changes, the financial statements may reflect different estimates, assumptions and judgements. Certain policies inherently rely more extensively on the use of estimates, assumptions, and judgements and as such may have a greater possibility of producing results that could be materially different than originally reported. Material estimates that are particularly susceptible to significant changes in the near term include estimates related to the determination of the allowance for credit losses on loans.

The Company’s significant accounting policies followed in the preparation of the unaudited consolidated financial statements are disclosed in Note 1 of the audited financial statements and notes for the year ended December 31, 2025 and are contained in the Company’s 2025 Annual Report on Form 10-K. There have been no significant changes to the application of significant accounting policies since December 31, 2025 .

Recent Accounting Pronouncements

In November 2025, the Financial Accounting Standards Board (FASB) issued ASU 2025-08, “Financial Instruments—Credit Losses (Topic 326): Purchased Loans.” The amendments in this ASU expand the population of acquired financial assets accounted for using the gross-up approach. Acquired loans (excluding credit cards) are deemed purchased seasoned loans and accounted for using the gross-up approach upon acquisition if criteria established by the new guidance are met. This change aims to enhance comparability, consistency, and better reflect the economics of acquiring financial assets. This ASU is effective for annual reporting periods beginning after December 15, 2026, and for interim reporting periods within those annual reporting periods. Early adoption is permitted in an interim or annual reporting period in which financial statements have not yet been issued or made available for issuance. If an entity adopts this ASU in an interim reporting period, it should apply it as of the beginning of that interim reporting period or the beginning of the annual reporting period that includes that interim reporting period. The Company does not expect the adoption of ASU 2025-08 to have a material impact on its consolidated financial statements.

Other accounting standards that have been issued by the FASB or other standards setting bodies are not currently expected to have a material effect on the Company's financial position, results of operations or cash flows.