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Idaho Federal Estate Tax Guide
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Idaho Federal Estate Tax Guide

Idaho has no estate, inheritance or gift tax. Only the federal estate tax can reach an Idaho estate, and it starts above $15 million for a 2026 death.

By Settled Editorial

Idaho collects no estate tax, no inheritance tax and no gift tax. The only death tax that can reach an Idaho estate is the federal estate tax, and for a death in 2026 it starts above $15,000,000 of gross estate plus lifetime taxable gifts. Almost no Idaho family will owe any of it.

This page covers that federal tax and the Idaho rules that sit beside it: Part 13 of Title 15, Chapter 3, which decides who inside the estate bears the bill, the Idaho fiduciary income tax on Form 66, and the separate claim deadline Idaho gives its own tax collector. It does not cover the new basis heirs receive on inherited property. That is an income tax rule, and the Idaho step-up in basis guide handles it.

A note on sources. Every Idaho rule below was read on September 24, 2026 at the section pages of the Idaho Code on legislature.idaho.gov, and the tax statements at tax.idaho.gov. Federal figures come from the IRS and the United States Code.

Idaho's Estate Tax Ended With Deaths In 2004

The Idaho State Tax Commission puts it in one sentence: "Idaho has no gift tax or inheritance tax, and its estate tax for deaths expired in 2004." The same page sends questions about deaths before January 1, 2005 to the Commission by phone. For anyone who died on or after that date, Idaho has no death tax return, no Idaho deadline and nothing to pay.

The Idaho Code tells the same story in its table of contents. Title 14 is still called "Estates of Decedents," and its chapter list shows Chapter 2 (escheats), Chapter 3 (wills) and Chapter 4, Estate and Transfer Tax, each marked repealed. The only chapters left in force are Chapter 1 on public administrators and Chapter 5, the Revised Unclaimed Property Act.

Two practical points follow:

  • No Idaho return means no Idaho clock. The nine month deadline discussed below is federal. Idaho adds nothing to it.
  • Another state's tax can still reach Idaho families. If the person who died owned real estate in a state that levies an estate or inheritance tax, that state can tax the property inside its borders. Idaho's apportionment act counts a "federal, state, or foreign tax" imposed because of a death as an estate tax, so it also decides who bears that bill. Inheritance taxes are the one exception in the definition.

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The Federal Number For A 2026 Death

Internal Revenue Code Section 2010(c)(3)(A) sets the exclusion at $15,000,000. The IRS says Public Law 119-21, signed July 4, 2025, amended Section 2010(c)(3) to reach that figure for calendar year 2026.

The IRS publishes the filing threshold by year of death:

Year of deathFiling threshold
2024$13,610,000
2025$13,990,000
2026$15,000,000

A return is required when the gross estate, increased by the decedent's adjusted taxable gifts and specific gift tax exemption, exceeds the threshold for the year of death. That measure has nothing to do with the size of the Idaho probate file, and nothing to do with what heirs keep after debts.

For deaths after 2026, Section 2010(c)(3)(B) indexes the figure for inflation using calendar year 2025 as the base, rounded to the nearest $10,000. Any page quoting the 2026 figure a few years from now will be quoting a stale number.

Above the threshold, the rate schedule in Internal Revenue Code Section 2001(c) tops out at 40 percent on the amount of taxable transfers above $1,000,000. Only the part above the exclusion is reached, so the effective rate on a whole estate stays well under 40 percent.

What Counts In The Gross Estate For An Idaho Family

The IRS describes the gross estate as everything the decedent owned or had certain interests in at death, at fair market value: cash, securities, real estate, insurance, trusts, annuities and business interests. Debts, administration costs, and property passing to a surviving spouse or a qualified charity come off to reach the taxable estate.

For an Idaho family the gross estate is usually bigger than the probate estate, for three reasons.

  • Beneficiary designations still count. Idaho Code 15-6-201 treats a payable on death provision in an insurance policy, deposit agreement, pension plan or similar written instrument as nontestamentary, which lets those assets skip probate. Skipping probate does not take them out of the federal gross estate. Idaho has no real-property transfer on death deed, so the house usually moves by will, trust or survivorship title instead. The avoid probate in Idaho guide explains each route.
  • Community property splits in half. A married decedent's gross estate generally counts the decedent's one-half community interest. Idaho Code 32-906(1) makes property acquired after marriage community property, so for most long marriages half of nearly everything is in the first spouse's estate and half is not.
  • Life insurance and retirement accounts follow ownership. A policy the decedent owned counts even though the proceeds go to a named beneficiary.

The Idaho small estate affidavit figure answers none of this. It decides whether a successor can collect personal property without opening probate, and being under it or over it tells you nothing about a federal return. The Idaho small estate affidavit guide covers what that route is for.

Deductions That End The Question For Most Families

The marital deduction. Property left outright to a surviving spouse who is a United States citizen passes free of federal estate tax with no dollar cap, which is why most married couples owe nothing at the first death. Internal Revenue Code Section 2056(d) takes the deduction away when the surviving spouse is not a United States citizen, unless the property passes into a qualified domestic trust.

The charitable deduction. Property left to a qualified charity comes off dollar for dollar.

Funeral costs, debts and the cost of administering the estate come off too.

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The Community Property Angle: A Second Basis Reset

This is the Idaho tax rule that matters to far more families than the estate tax, and it sits in the income tax code.

Internal Revenue Code Section 1014(b)(6) gives a new basis to "property which represents the surviving spouse's one-half share of community property," as long as at least one half of the whole community interest was includible in the deceased spouse's gross estate. In plain terms, both halves of an Idaho couple's community property can reset to date of death value at the first death, not just the deceased spouse's half.

Idaho's definition is broad. Idaho Code 32-906(1) says the income, rents, issues and profits of all property, separate or community, are community property unless the conveyance or a written agreement between the spouses says otherwise. The Idaho community property guide walks through how to classify each asset, and the Idaho step-up in basis guide covers what the reset does to a later sale.

Who Pays The Federal Tax: Idaho's Apportionment Act

Idaho adopted the Uniform Estate Tax Apportionment Act as Part 13 of Title 15, Chapter 3, in 2004. Idaho Code 15-3-1314(a) says its apportionment rules, sections 15-3-1303 through 15-3-1307, do not apply to the estate of anyone who died before January 1, 2005. For every later death, here is how the bill gets divided.

The documents decide first

Idaho Code 15-3-1303(a) sets an order:

  1. The will. Where the will "expressly and unambiguously directs the apportionment of an estate tax," the tax is apportioned that way "regardless of whether such will is probated."
  2. A revocable trust. Whatever the will leaves open follows an express direction in a revocable trust the decedent created. If two trusts conflict, the most recently dated instrument prevails.
  3. Any other dispositive instrument. A beneficiary designation or other instrument can say whether the property it passes bears its own share of the tax.

Idaho added something most states do not have. Idaho Code 15-3-1303(d) prints sample clauses that satisfy the "express and unambiguous" test, such as a will clause saying all taxes arising from the death "shall be paid out of the residue of my probate estate." Other wording can work, but where a court finds a clause unclear about any part of the tax, the statute apportions that part instead.

Where no document controls

Idaho Code 15-3-1304(1) apportions the estate tax "ratably to each person that has an interest in the apportionable estate." The definition in 15-3-1302(a) is what makes this fair to the family:

  • The apportionable estate is the gross estate reduced by claims and expenses the tax allows as deductions, and by the value of any interest that qualifies for the marital or charitable deduction.
  • So a surviving spouse's deductible share and a charity's share are left out of the pool and carry none of the tax by default. The children and other beneficiaries whose shares generated the tax pay it in proportion to what they take.

The apportionable estate reaches nonprobate property too, because it starts from the federal gross estate. A payable on death account holder or a life insurance beneficiary can be charged a ratable share even though the asset never passed through the Idaho court.

What the personal representative can do about it

Idaho Code 15-3-1308 lets a fiduciary protect the estate before anything goes out:

  • (a) defer a distribution until satisfied that adequate provision for the tax has been made;
  • (b) withhold from a distributee the amount of tax apportioned to that person's interest;
  • (c) require a bond or other security as a condition of distribution.

Idaho Code 15-3-1309(a) lets a fiduciary responsible for paying the tax collect the apportioned share from any person. When one person's share cannot be collected, 15-3-1309(b) lets the fiduciary collect it from others in a set order, starting with people holding interests in the apportionable estate that are not exonerated. Section 15-3-1309(d) caps what anyone pays at the value of that person's interest, and 15-3-1310 gives anyone who paid more than their share a right to reimbursement from the others.

When the family disagrees, Idaho Code 15-3-1311 lets a fiduciary, transferee or beneficiary ask a court to determine and enforce the act, including by declaratory judgment, or petition under 15-3-704 for a probate estate or 15-7-201 for a trust. The Idaho executor duties guide covers the personal representative's tax filings alongside the rest of the job.

Portability, And The Filing Nobody Thinks They Need

When the first spouse dies, the unused part of that spouse's exclusion can pass to the survivor. Internal Revenue Code Section 2010(c)(4) calls it the deceased spousal unused exclusion amount and sets it at the lesser of the exclusion for the year or the unused amount of the last deceased spouse. A survivor cannot stack unused amounts from several marriages.

The catch is in Section 2010(c)(5)(A). The survivor can use that amount only if the executor of the first spouse's estate files an estate tax return computing it and makes the election on that return. The election is irrevocable, and no election may be made on a return filed after the time prescribed by law, including extensions.

So an Idaho family whose first death is nowhere near $15,000,000 may still want to file Form 706 purely to keep the election. The IRS Form 706 instructions describe an extension under Revenue Procedure 2022-32 for an executor who had no filing requirement and missed the deadline: the return can still be filed on or before the fifth anniversary of the death, stating at the top that it is "Filed Pursuant to Rev. Proc. 2022-32 to Elect Portability under section 2010(c)(5)(A)."

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Three Clocks That Do Not Line Up

The federal return. Form 706 is due nine months after the date of death. Form 4768 requests an automatic six month extension of time to file. The tax itself is still due at nine months unless you separately ask for more time to pay.

The Idaho probate window. Idaho Code 15-3-108 says no informal or formal probate or appointment proceeding may start more than three years after the death, with narrow exceptions. The federal return and the portability election both close long before that. See the Idaho probate timeline for the rest of the calendar.

Idaho's own tax claims. Idaho treats state taxes differently from every other creditor. Idaho Code 15-3-803(a) and (c) carve state taxes out of the ordinary claim deadlines, and 15-3-803(d) gives them their own rule. A state tax claim is barred unless presented within the earlier of:

  • three years from the latest of the date of death, the return's due date (without extensions) or the date the return was filed; or
  • the time in Idaho Code 63-3068(e), if the Tax Commission received written notice under that section.

Section 63-3068(e) is the tool worth knowing. For income the decedent received while alive, or the estate received during administration, the Commission must act within twelve months after the executor or other fiduciary files a written request for prompt action. That shortens the state's window from three years to one, but it does not apply until the return the request relates to has been filed. Section 15-3-803(e) also keeps the Commission free to assess taxes on the estate's own transactions, and taxes for which no return was ever filed. The Idaho creditor claims guide covers how the other claims run.

One Idaho filing helps with the federal return. Idaho Code 15-3-706 gives the personal representative three months after appointment to prepare an inventory showing each item's fair market value "as of the date of the decedent's death," the same values the federal schedules use. The representative must send a copy to interested persons who ask for one, and may file the original with the court, so filing is optional.

The Tax Idaho Does Charge An Estate Is An Income Tax

Idaho taxes what the estate earns, not what it is worth.

Idaho Code 63-3024(1) imposes a tax on "every individual, trust, or estate required by this chapter to file a return," and 63-3024(2)(a) sets the rate for individuals, trusts and estates at 5.3% of taxable income over $2,500. Section 63-3024(3) has the Tax Commission adjust that threshold every year for inflation, so check the current Form 66 instructions for the figure that applies.

Idaho Code 63-3030(a)(5) requires a return from every Idaho resident estate with gross income of $600 or more for the tax year, and 63-3030(a)(6) reaches a nonresident estate with more than $600 of Idaho-source gross income. The Tax Commission says an estate is a resident estate if the decedent was domiciled in Idaho on the date of death, and it asks for a complete copy of the federal return with the Idaho one. The Idaho return is Form 66, the Fiduciary Income Tax Return. Idaho can also require a final individual return, Form 40 or Form 43, for the decedent's last tax year.

An estate that holds a rental house in Nampa for a year and collects rent has Idaho taxable income. An estate that earns nothing usually files neither a federal Form 1041 nor an Idaho Form 66. Neither situation has anything to do with the federal estate tax.

What An Idaho Family Should Do Next

  1. Add it up once, the federal way. Count the house, life insurance the decedent owned, retirement accounts and anything with a beneficiary form, and count only the decedent's half of community property. If the total is far below $15,000,000, no federal estate tax applies and no Form 706 is required.
  2. If a spouse died, look at portability. The election is the main reason modest estates file a Form 706, and Revenue Procedure 2022-32 offers a five year path for a missed one.
  3. Read the will and the trust before you distribute. A clear tax clause controls under Idaho Code 15-3-1303. Without one, 15-3-1304 spreads the tax ratably, and 15-3-1308 lets you hold back or take security first.
  4. File the income returns. The decedent's final Form 1040 and Idaho return, and the estate's Form 1041 and Idaho Form 66 once gross income reaches $600, are the returns most Idaho estates actually file.
  5. Consider the prompt-action request. Once the Idaho returns are filed, a written request under Idaho Code 63-3068(e) gives the Tax Commission twelve months to act, which can let you close the estate sooner.
  6. Get help when the facts are hard. A business, a farm or ranch, a surviving spouse who is not a citizen, property in a state that taxes estates, or a gross estate anywhere near the threshold are the cases where a CPA and an Idaho estate attorney earn their fee.

If you are settling a house rather than planning around a tax, the selling inherited property in Idaho guide picks up from here, and the Idaho probate guide covers the court side. To check one estate against the federal exemption, the Idaho estate tax page runs the numbers and confirms that Idaho adds no estate tax of its own.

Frequently Asked Questions

Does Idaho have an estate tax or an inheritance tax?

No. The Idaho State Tax Commission states that Idaho has no gift tax or inheritance tax, and that its estate tax for deaths expired in 2004. The Idaho Code matches: Title 14, Estates of Decedents, lists Chapter 4, Estate and Transfer Tax, as repealed, and the only live chapters left in that title cover public administrators and unclaimed property. For a death on or after January 1, 2005 there is no Idaho death tax return to file.

How large does an Idaho estate have to be before federal estate tax applies?

For a death in 2026 the exclusion is $15,000,000 per person. Internal Revenue Code Section 2010(c)(3)(A) sets that figure, and the IRS says Public Law 119-21, signed July 4, 2025, raised it for calendar year 2026. The IRS filing threshold table lists $13,610,000 for 2024, $13,990,000 for 2025 and $15,000,000 for 2026, measured against the gross estate increased by adjusted taxable gifts and the specific gift tax exemption.

Who pays the federal estate tax out of an Idaho estate?

The will decides first, then a revocable trust, then any other instrument, and Idaho's statute fills whatever they leave open. Idaho Code 15-3-1303 follows a will that expressly and unambiguously directs apportionment, whether or not the will is probated. Where no instrument controls, Idaho Code 15-3-1304(1) apportions the tax ratably to each person with an interest in the apportionable estate. Property that qualifies for the marital or charitable deduction comes out of the apportionable estate under 15-3-1302(a)(2), so a surviving spouse's or a charity's deductible share carries none of the tax by default.

Does Idaho tax an estate's income?

Yes, and that is a different tax from an estate tax. Idaho Code 63-3024(2)(a) taxes individuals, trusts and estates at 5.3% of taxable income over $2,500, a threshold the Tax Commission adjusts for inflation under 63-3024(3). Idaho Code 63-3030(a)(5) requires a return from every Idaho resident estate with gross income of $600 or more for the year. The return is Idaho Form 66, the Fiduciary Income Tax Return.

Is the Idaho probate deadline the same as the federal estate tax deadline?

No. Form 706 is due nine months after the date of death, and Form 4768 requests an automatic six month extension to file, though the tax is still due at nine months. Idaho Code 15-3-108 lets an informal or formal probate or appointment proceeding start up to three years after the death. A family that waits on the Idaho window can miss the federal return and the portability election it carries.

Why does community property matter for federal tax in Idaho?

Because of the basis rule, which touches far more Idaho families than the estate tax does. Internal Revenue Code Section 1014(b)(6) gives the surviving spouse's one-half share of community property a new basis at the first death, as long as at least half of the whole community interest was includible in the deceased spouse's gross estate. Idaho Code 32-906(1) makes property acquired after marriage community property, and even the income from separate property is community unless a written instrument says otherwise.

Related Idaho Guides

This guide is general information about Idaho estates and federal transfer taxes. Tax figures change every January and apportionment turns on the words of the will and trust, so confirm anything that affects your situation with a CPA or a licensed Idaho attorney.

Sources:

It is not legal advice.

Information current as of September 24, 2026

Settled Estate is not a law firm, and this content is for informational purposes only and does not constitute legal advice. Probate laws and procedures in Idaho can change. Consult with a qualified attorney for advice specific to your situation. Full disclaimer.

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