Important: This article is general educational information, not tax or legal advice. Filing rules and deadlines have exceptions. An executor should confirm requirements with the IRS instructions or a licensed CPA or attorney.
Quick answer: Form 706 is the federal estate tax return. It is generally due nine months after the date of death, and a six-month extension is available. An executor must file when the estate is large enough to be subject to federal estate tax, and may choose to file even when no tax is due in order to elect portability for a surviving spouse.
What Is Form 706?
Form 706 is the United States Estate (and Generation-Skipping Transfer) Tax Return. It reports the value of the decedent’s gross estate, deductions, and any tax due. The IRS publishes the form and its instructions (IRS: Instructions for Form 706).
Who Must File?
The executor generally must file when the gross estate, plus certain lifetime taxable gifts, exceeds the basic exclusion amount for the year of death. For deaths in 2026, that amount is $15 million (Bowditch & Dewey). Gross estate includes real estate, investments, retirement accounts, business interests, assets in a revocable trust, and life insurance the person owned. See the full explanation in Federal Estate Tax Exemption 2026.
When Is a Filing Optional but Smart?
Many estates are under the threshold and are not required to file. But a surviving spouse can inherit the deceased spouse’s unused exemption, called the DSUE amount, only if the executor elects portability on a timely filed Form 706 (Taxstra). If the survivor’s own estate later grows beyond the exemption, this election can matter a lot. Portability does not apply to the separate generation-skipping transfer exemption, and most states do not offer state-level portability.
Deadlines
| Item | Rule |
|---|---|
| Due date | Nine months after the date of death |
| Extension | Automatic six-month extension to file by submitting Form 4768 before the due date (an extension to file is not an extension to pay) |
| Late portability election | Simplified relief may be available up to five years after death for estates not otherwise required to file, under IRS Rev. Proc. 2022-32 |
Sources: IRS Notice 2011-76 and IRS Rev. Proc. 2022-32. If a deadline falls close, ask a CPA right away.
What You Need to Gather
- Date-of-death values for real estate, accounts, and business interests (appraisals where needed)
- Life insurance policy statements and beneficiary information
- Records of debts, funeral costs, and administration expenses
- Records of prior taxable gifts (Form 709 returns)
- The will, any trust documents, and the marriage certificate if claiming the marital deduction
Valuation and Basis
Assets are normally valued at fair market value on the date of death. The values reported on Form 706 can also affect an heir’s tax basis. See Step-Up in Basis: How It Saves Heirs Money.
Form 706 and State Taxes
A federal filing does not replace state returns. Twelve states and D.C. have an estate tax, and five states have an inheritance tax. See states with an estate tax in 2026 and states with an inheritance tax in 2026.
Frequently Asked Questions
Do I need Form 706 if the estate is under $15 million?
Not usually for federal tax. But you may want to file to elect portability for a surviving spouse.
Who files Form 706?
The executor or personal representative of the estate.
What if I missed the nine-month deadline?
Ask a CPA or attorney quickly. Penalties may apply, and a late portability election may still be possible within five years.
Is Form 706 the same as the inheritance tax return?
No. Form 706 is the federal estate tax return. Inheritance tax returns are state forms. Read Inheritance Tax vs. Estate Tax.
Sources
- IRS: Instructions for Form 706
- IRS: Notice 2011-76
- IRS: Rev. Proc. 2022-32 (late portability election)
- Additional references consulted (not linked): 26 U.S.C. §§2010 and 2056, Taxstra, and Bowditch & Dewey.
How We Prepared This Article
We start with primary sources, such as IRS forms, instructions, and notices, and then compare with reputable secondary publications. Deadlines and thresholds are reviewed at least twice a year and whenever the law changes. This website is an educational publisher, not a law firm or CPA firm.
When to Get Professional Help
If you are an executor, a filing deadline is approaching, or you want to elect portability, talk to a licensed estate attorney or CPA as soon as possible.
Keep Reading
- What Does an Executor Do? Duties and Pay
- What Is Probate? How It Works Step by Step
- How Long Does Probate Take?
- Revocable vs. Irrevocable Trust
Last reviewed: October 4, 2026
Next review due: April 4, 2027
Disclaimer: This content is for general information only and is not tax or legal advice. Consult a licensed CPA or attorney about your situation.