Form 1040 Schedule 1 Instructions 2025. The 1040 schedule 1, commonly referred to as additional income and adjustments to income, is a crucial form used alongside the standard form 1040 for federal income tax filings in the united states. You or your spouse only need to fill this out if you filed.

Federal income tax return that many taxpayers must complete. When filing tax returns in 2025, marginal tax rates for 2024 apply.