Estate Tax Filing Deadline: When Returns Are Due

Three Tax Returns, Three Deadlines

Estate administrators typically face three separate tax obligations, each with its own filing deadline. Missing any of them can trigger penalties, interest, and in some cases personal liability for the administrator.

The decedent's final Form 1040 covers income earned from January 1 through the date of death. It's due on the normal April 15 filing deadline for the year the person died. If someone dies in 2026, their final 1040 is due April 15, 2027. If the death occurs between January 1 and April 15, you're also responsible for the prior year's return if it hasn't been filed yet.

Form 1041 (estate income tax return) is required when the estate generates $600 or more in gross income during administration, or meets another filing requirement. Interest on bank accounts, rental income from property, dividends from stocks — anything the estate earns after the date of death gets reported here. The fiscal year is flexible: you can choose a calendar year or a fiscal year ending in any month within 12 months of the date of death.

Form 706 (federal estate tax return) is generally required when the gross estate plus adjusted taxable gifts exceeds the $15 million threshold for someone dying in 2026. A Form 706 may also be filed below that threshold to elect portability of a deceased spouse's unused exclusion. The return is due 9 months after the date of death; a 6-month filing extension is available by filing Form 4768, but the extension does not extend the time to pay tax. The vast majority of estates fall below the threshold and don't need to file Form 706 unless an election such as portability is needed.

Key Deadlines at a Glance

State-Level Estate and Inheritance Taxes

Twelve states and D.C. impose their own estate taxes, often with lower exemption thresholds than the federal $15 million for 2026. Five states impose inheritance taxes (paid by the recipient, not the estate). Maryland has both.

States with estate taxes include Connecticut, Hawaii, Illinois, Maine, Maryland, Massachusetts, Minnesota, New York, Oregon, Rhode Island, Vermont, Washington, and D.C. For 2026, exemptions range from $1 million in Oregon to $15 million in Connecticut; Massachusetts's threshold is $2 million.

States with inheritance taxes — Kentucky, Maryland, Nebraska, New Jersey, and Pennsylvania — tax the heir based on their relationship to the deceased. Spouses are exempt everywhere, but siblings, nieces, nephews, and non-relatives can face rates from 4.5% to 16%.

What Happens If You Miss a Deadline

The failure-to-file penalty is 5% of the unpaid tax per month, up to 25%. The failure-to-pay penalty adds 0.5% per month. Interest accrues on both. These amounts come from the estate, but if the estate can't pay — because you distributed assets to heirs before settling tax obligations — the IRS can pursue you personally as the administrator.

Filing for an extension avoids the failure-to-file penalty but doesn't extend the deadline for paying the tax owed. You still need to estimate and pay what's due by the original deadline.

Practical Steps for Administrators

Apply for an Employer Identification Number (EIN) for the estate immediately after appointment — you'll need it to open the estate bank account and file the 1041. You can get one instantly on the IRS website.

Gather the deceased's prior-year returns, W-2s, and 1099s to identify income sources. File Form 4506-T to request tax transcripts from the IRS if you don't have access to the deceased's records — the transcripts reveal bank accounts, brokerage accounts, and employers that generated taxable income.

The When There's No Will — Intestacy Survival Guide includes a tax deadline tracker, a document checklist for each return, and a step-by-step walkthrough of the Form 1041 filing process.