How Do I File Taxes for a Deceased Person in Idaho?

Idaho requires a final state income tax return for the decedent alongside the federal Form 1040; a federal estate tax return (Form 706) is required only for estates above $15,000,000.

State

Approximate Estate Value

Estate Earns Income

YesNo

Date of Death

Two returns are due.

IRS Form 1040 and Form 40.

Federal

Final income tax return

A final federal income tax return is required for income earned from January 1 through the date of death.

Form: IRS Form 1040
Due: April 15 following year of death

Write "DECEASED," the decedent's name, and the date of death across the top of the return. If filing jointly with a surviving spouse, include both incomes. Attach Form 1310 to claim a refund, unless you are the surviving spouse filing a joint return or a court-appointed personal representative attaching a copy of the court certificate to the original return.

IRS Form 1040 File online

Idaho

Final income tax return

A final state return is required for income earned through the date of death.

Form: Form 40
Due: April 15 following year of death

File Form 40 (resident) or Form 43 (part-year/nonresident) for income through the date of death (Idaho Code § 63-3030(a)(1)). Check the "Deceased in [year]" box beside the decedent's name.

Form 40 File online

Tax clearance

No tax clearance is required in Idaho

No tax clearance required. Idaho has no estate, inheritance, or gift tax. The estate tax applied only to deaths before January 1, 2005, and the entire chapter was repealed in 2020.

Not required

Federal estate income tax return: IRS Form 1041 is only required if the estate earns $600 in gross income or more during administration.
Federal estate tax return: The estate value ($0) is below the federal exemption of $15,000,000. IRS Form 706 is generally not required.
Idaho estate income tax return: A fiduciary return is only required if the estate earns income above the filing threshold (Resident estate: gross income $600 or more. Nonresident estate: Idaho-source gross income over $600. Resident trust: gross income $100 or more and required to file a federal return. Nonresident trust: Idaho-source gross income over $100 and required to file a federal return).

General information about tax filing requirements after a death, not tax or legal advice. Consult a licensed tax professional for tax questions. Data verified Sep 15, 2026

At minimum, a final federal income tax return (Form 1040) for income earned through the date of death, and Idaho requires a final state income tax return (Form 40) as well. If the estate earns income during administration, a federal fiduciary return (Form 1041) and an Idaho fiduciary return (Form 66) may also be required.

The final federal income tax return is due April 15 following year of death. The final Idaho return is due April 15 following year of death. The Idaho fiduciary return is due April 15 (calendar year), or the 15th day of the 4th month after a fiscal year ends.

No tax clearance required. Idaho has no estate, inheritance, or gift tax. The estate tax applied only to deaths before January 1, 2005, and the entire chapter was repealed in 2020. Every tax obligation is still settled before the final distribution.

No. Idaho imposes no state estate tax and no inheritance tax. The tax filings after a death are the income tax returns (the final return and, where the estate earns income, the estate income tax return). Only the federal estate tax applies, and only to an estate above $15,000,000.

Yes. Estate size does not change the final income tax return: a final Form 1040 is filed whatever the estate is worth if the decedent had income. What a smaller estate avoids is the federal estate tax return (Form 706), due 9 months after date of death (6-month extension available) and required only above $15,000,000.

Tax Filing After Death in Idaho

After a death in Idaho, both federal and state tax returns must be filed. A final income tax return covers the deceased's income through the date of death, and a separate fiduciary return may be needed if the estate earns income during administration. A federal estate tax return (Form 706) is required only for estates above the federal exemption of $15,000,000.

With no state estate or inheritance tax, tax filing after death in Idaho focuses on income tax obligations — the final return and, where the estate earns income, a fiduciary return.

Filing deadlines depend on the type of return. The final Idaho income tax return is due April 15 following year of death. The Idaho estate settlement plan tracks all deadlines in order.

SimplyTrust Editorial·Updated September 20, 2026

Legal Sources

Data sourced from Idaho statutes and official state code. How we research.

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