Form 1040
Form 1040 is the standard IRS individual income tax return that US citizens and resident aliens use to report annual income, calculate federal tax liability, claim deductions and credits, and determine whether a refund is owed or additional tax is due.
Form 1040 serves as the central document of the US individual income tax system. Every year, the IRS requires taxpayers with income above specified thresholds to file this return by the April 15 deadline — or by the extended October 15 deadline if they request an automatic six-month extension using Form 4868. The form consolidates income from wages, self-employment, investments, retirement distributions, rental properties, and other sources onto a single summary sheet, which then feeds into the tax computation.
The 2018 tax reform under the Tax Cuts and Jobs Act (TCJA) substantially redesigned the 1040 into a shorter postcard-style form supplemented by numbered schedules. Schedule 1 captures additional income sources and above-the-line deductions such as student loan interest and self-employed health insurance premiums. Schedule B reports taxable interest and ordinary dividends exceeding $1,500. Schedule D consolidates capital gains and losses from investment activity, drawing from Form 8949 where individual transactions are listed. Schedule E covers supplemental income from partnerships, S corporations, estates, trusts, and rental real estate.
Filers choose between the standard deduction and itemized deductions on Schedule A. The TCJA nearly doubled the standard deduction — indexed to inflation annually — which caused the share of filers itemizing to drop sharply. Itemized deductions include mortgage interest, state and local taxes (subject to the $10,000 SALT cap), charitable contributions, and certain unreimbursed medical expenses exceeding 7.5 percent of adjusted gross income.
Investment income flows to the 1040 through several pathways. Qualified dividends and long-term capital gains are taxed at preferential rates of 0, 15, or 20 percent depending on taxable income, and high-income filers may also owe the 3.8 percent Net Investment Income Tax reported on Form 8960. Wash sales, inherited assets with stepped-up basis, and tax-loss harvesting all affect Schedule D entries. Retirement account distributions appear on line 4 (IRA) or line 5 (pensions and annuities) with applicable taxable amounts driven by prior after-tax contributions tracked on Form 8606.
The IRS Free File program allows taxpayers with adjusted gross income below a threshold set each year to use commercial software at no cost. The IRS Direct File pilot, expanded nationally for the 2024 filing season, permits eligible filers with straightforward returns to file directly with the IRS for free. Regardless of filing method, the 1040 remains the authoritative record of annual federal tax obligations and forms the basis for state returns in most jurisdictions that use federal adjusted gross income as their starting point.