Tax Deadlines After Death in New York: The Complete Timeline

One of the things that catches New York executors most off guard is discovering that post-death taxes aren't a single filing — they're a cascade of separate deadlines, each with its own form, its own agency, and its own penalty structure. Missing any of them can mean interest, penalties, and in some cases personal liability for the executor.

Here's every deadline you need to track, in the order they typically fall.

Deadline 1: The Decedent's Final Income Tax Return

Due: April 15 of the year following death (or next business day)

The decedent's final income tax return covers all personal income earned from January 1 of the year of death through the exact date of death. Two returns are required:

• Federal Form 1040: filed with the IRS
• New York Form IT-201 (resident) or IT-203 (nonresident/part-year resident): filed with the NYS Department of Taxation and Finance

If the decedent was married, the surviving spouse can elect to file a joint return for the final year — provided they don't remarry before December 31 of that year. Filing jointly usually provides better rates and a higher standard deduction.

The return is filed under the decedent's Social Security Number, not an EIN. Write "DECEASED," the decedent's name, and the date of death at the top of the return. If the IRS owes a refund, Form 1310 must be filed with the federal return to direct the refund to the executor.

Extensions are available: IRS Form 4868 and NY Form IT-370 grant automatic six-month extensions to October 15. However, an extension to file is not an extension to pay — any tax owed is due by April 15 regardless.

Deadline 2: Quarterly Estimated Taxes for the Estate Entity

Due: Standard quarterly dates (April 15, June 15, September 15, January 15)

At the moment of death, the decedent's probate assets move into a new legal entity: the estate. If the estate generates income — from rental properties, dividends, interest, or any other source — that income is taxable to the estate.

If the estate is expected to owe more than $1,000 in federal income tax ($1,000 in NY) for the year, the executor should make estimated quarterly tax payments using Form 1041-ES (federal) and NY Form IT-2106 (state). Failing to make estimated payments results in underpayment penalties at year-end.

Many executors don't realize this deadline exists. The estate is treated as a taxable entity separate from the decedent and separate from the beneficiaries. It needs its own EIN (obtained via IRS Form SS-4) and its own tax filings.

Deadline 3: The New York State Estate Tax Return (ET-706)

Due: 9 months from the date of death

This is the most consequential deadline in New York estate administration. If the decedent's gross estate — including all probate and non-probate assets, plus any taxable gifts made within three years before death — exceeds the New York basic exclusion amount (currently $7,350,000 for deaths in 2026), the estate must file Form ET-706 and pay the resulting tax.

The 9-month deadline is firm. There is no grace period.

What happens if you miss it: Interest accrues at the tax rate plus a penalty rate from the original due date. New York imposes both failure-to-file and failure-to-pay penalties. The interest compounds.

Estate tax extension — Form ET-133: If the estate cannot be fully valued and the return cannot be accurately completed within nine months, the executor can file Form ET-133 (Application for Extension of Time to File and/or Pay Estate Tax) to request a six-month extension to file. The extended filing deadline becomes 15 months from the date of death.

Critical caveat: Form ET-133 extends the time to FILE — it does not extend the time to PAY. At the nine-month deadline, the estate must remit an estimated payment of the tax owed based on the best information available. If the actual tax turns out to be higher than the estimate when the return is eventually filed, interest accrues on the underpaid amount from the original nine-month due date.

File ET-133 before the nine-month deadline. Do not wait until the deadline passes.

Deadline 4: The Federal Estate Tax Return (Form 706)

Due: 9 months from the date of death (same as NY)

Federal estate tax applies to estates above the federal basic exclusion amount, which for deaths in 2026 is $15,000,000 (as increased under the "One Big Beautiful Bill").

Most New York estates that trigger the NY estate tax (above $7,350,000) will not trigger federal estate tax (the federal bar is more than double the NY bar). But there's an important reason an executor may still need to file federal Form 706 even when no federal tax is owed: portability.

The federal system allows a surviving spouse to inherit the deceased spouse's unused federal exemption (the "Deceased Spousal Unused Exclusion" or DSUE) — but only if the executor files Form 706 within nine months of death (or within the extended period if ET-133 is filed). Without filing Form 706, the DSUE is permanently lost.

Note: New York does not recognize federal portability for state estate tax purposes. Filing Form 706 for portability helps the surviving spouse's federal position only, not their New York state position.

Extension for federal Form 706: Use IRS Form 4768 to request a six-month extension to file. Like ET-133, Form 4768 extends the filing deadline but not the payment deadline — estimated taxes must be paid by the original nine-month due date.

Deadline 5: The Fiduciary Income Tax Return

Due: April 15 following each tax year the estate is open (or 3.5 months after a fiscal year end)

If the estate generates $600 or more in gross income in any tax year, the executor must file:

• Federal Form 1041 (U.S. Income Tax Return for Estates and Trusts)
• New York Form IT-205 (Fiduciary Income Tax Return)

These are filed for each year the estate remains open — which in New York can be two or more years for complex estates. If the estate has nonresident beneficiaries and derives income from New York sources, Form IT-205-A (Fiduciary Allocation) must also be filed.

If the estate distributes income to beneficiaries during the year, it claims a deduction on Form 1041 and issues Schedule K-1 to each beneficiary showing the income that passes to their personal return.

Extensions for fiduciary returns: IRS Form 7004 extends federal Form 1041 to September 30 (for calendar-year estates). New York Form IT-370-PF extends the IT-205 for six months.

The NY Estate Tax Closing Letter

After the ET-706 is filed and the tax is paid, the New York State Department of Taxation and Finance will eventually issue an Estate Tax Closing Letter formally confirming the tax liability has been resolved. This letter typically arrives roughly nine months after the ET-706 is filed — meaning for a typical estate where the return is filed at or near the nine-month due date, you're looking at approximately 18 months from the date of death before the closing letter arrives.

Most estate practitioners recommend waiting for the closing letter before making final distributions to beneficiaries. Distributing before the closing letter exposes the executor to potential personal liability if the Tax Department later asserts additional tax owed.

Summary Timeline

The New York Final Tax & Estate Tax Guide provides the complete forms-and-deadlines map for New York estates, with practical guidance on calculating estimated payments, timing the ET-133 extension, and coordinating the fiduciary income tax filings with the estate tax timeline.

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