The taxable estate is the gross estate minus every deduction the Internal Revenue Code allows, and that single subtraction under IRC 2051 produces the figure the federal estate tax is calculated on.1Office of the Law Revision Counsel. 26 USC 2051 – Definition of Taxable Estate For a decedent dying in 2026, only the portion above the $15 million basic exclusion amount actually faces tax, and the top rate is 40%.2Office of the Law Revision Counsel. 26 USC 2010 – Unified Credit Against Estate Tax
The arithmetic is simple. Getting the inputs right is not. The gross estate is broader than most people assume, and the deductions have conditions that quietly disqualify sloppy planning.
What Counts in the Gross Estate
The gross estate includes the fair market value of everything the decedent held an interest in at death: real estate, bank accounts, investment portfolios, business interests, vehicles, personal property, and intangibles like patents or royalties. For a U.S. citizen or resident, location is irrelevant. Property anywhere in the world is in.
Three categories cause most of the surprises.
Jointly Held Property
Property held jointly with a surviving spouse who is a U.S. citizen follows a clean rule: exactly half the value goes into the gross estate, regardless of who actually paid for it. For any other joint ownership, the IRS presumes the full value belongs to the decedent. The executor can carve that down only by proving, with documentation, how much the surviving co-owner independently contributed.
Life Insurance
Life insurance proceeds land in the gross estate when the policy pays to the estate itself, or when the decedent held any “incidents of ownership” at death.3Office of the Law Revision Counsel. 26 USC 2042 – Proceeds of Life Insurance That phrase sweeps wider than people expect. It includes the power to change the beneficiary, to cancel or surrender the policy, to borrow against its cash value, or to hold a reversionary interest worth more than 5% of the policy’s value.
Someone who bought a $2 million policy, named the children as beneficiaries, and assumed the proceeds would bypass the estate is wrong if they still owned the policy at death. An irrevocable life insurance trust can solve the problem, but only if the transfer happened more than three years before death.
Transfers With Retained Control
Property given away during life still shows up in the gross estate if the decedent kept too much of the benefit or control.4Office of the Law Revision Counsel. 26 USC 2036 – Transfers With Retained Life Estate A parent who deeded a rental property to a child but kept collecting the rent still owns it for estate tax purposes. The same result follows for property in a trust if the decedent retained the right to income, the power to pick who benefits, or the ability to revoke the arrangement.
Annuities and certain retirement accounts round things out, included to the extent the decedent funded them.
Valuing What’s In
Every asset is valued at fair market value on the date of death. That is the default and the usual choice. The executor has one alternative: electing to value the entire estate as of six months after the date of death.5Office of the Law Revision Counsel. 26 USC 2032 – Alternate Valuation
The alternate valuation date exists for estates that lose value during that six-month window, such as a market crash or a steep drop in real estate prices. Two conditions attach. The election is only available if it actually reduces both the gross estate and the estate tax owed, and it applies to everything. Cherry-picking is not allowed. Any asset sold or distributed inside the six months is valued on the date it left the estate.
The Deductions
Once the gross estate is set, the deductions determine how much of it is actually taxable. Each one is a statutory allowance with its own conditions.
Administration Expenses and Debts
The estate deducts the cost of settling itself: executor commissions, attorney fees, accounting fees, court costs, and appraisal fees. Funeral expenses are deductible, including reasonable burial costs and perpetual care of the gravesite. Outstanding debts come off too — mortgages, credit card balances, medical bills, personal loans — provided they were owed for real value received rather than disguised gifts.
Federal rules cap these deductions at whatever the law of the state administering the estate would allow. If state law limits executor commissions, the federal deduction stops at the same point. The expenses also have to be genuine; inflated fees used to funnel wealth to family members will be disallowed.6eCFR. 26 CFR 20.2053-1 – Deductions for Expenses, Indebtedness, and Taxes; In General
Losses During Administration
If estate property is damaged by fire, storm, or another casualty, or stolen during administration, the uninsured portion is deductible. The loss must occur before the property is distributed. Once beneficiaries hold it, the loss is theirs. The estate also has to choose between deducting the loss on the estate tax return or on the estate’s income tax return. Not both.7eCFR. 26 CFR 20.2054-1 – Deduction for Losses
Charitable Transfers
Property left to qualifying charities comes out entirely, with no cap. The recipient must be a U.S. governmental entity or an organization operated exclusively for religious, charitable, scientific, literary, or educational purposes.8Office of the Law Revision Counsel. 26 USC 2055 – Transfers for Public, Charitable, and Religious Uses
Split-interest transfers — a trust that pays income to a child for twenty years before passing the remainder to charity, for example — face narrower rules. The charitable remainder must sit in a charitable remainder annuity trust, a charitable remainder unitrust, or a pooled income fund. Partial interests that don’t fit one of those approved structures are not deductible.
The Marital Deduction
For a married decedent, this is almost always the biggest reduction. The estate deducts 100% of the value of qualifying property passing to a surviving spouse who is a U.S. citizen. No dollar limit applies. The practical effect is that estate tax is deferred until the second spouse dies.
The main restriction is the terminable interest rule: property passing to the spouse generally doesn’t qualify if the interest will end and then pass to someone else. The important exception is Qualified Terminable Interest Property, or QTIP. A QTIP trust qualifies as long as the surviving spouse receives all the income at least annually and no one can redirect the principal to another person during the spouse’s lifetime. The executor has to affirmatively elect QTIP treatment on the return.
Non-Citizen Surviving Spouses
The unlimited marital deduction is not available for a direct bequest to a non-citizen spouse. To qualify, the property has to pass through a Qualified Domestic Trust. A QDOT needs at least one trustee who is a U.S. citizen or a domestic corporation, and no principal distributions can be made unless that trustee has the right to withhold the estate tax owed on the distribution.9Office of the Law Revision Counsel. 26 USC 2056A – Qualified Domestic Trust Without one, the property is fully taxable in the first estate, which can generate millions in avoidable tax.
A Worked Example
Suppose a decedent dies in 2026 with a gross estate of $20 million, $2 million in allowable deductions, and $1 million in adjusted taxable gifts made during life.
- Gross estate: $20 million
- Less deductions: $2 million
- Taxable estate: $18 million
- Plus adjusted taxable gifts: $1 million
- Combined transfer: $19 million
The tentative tax is calculated on $19 million using the rate schedule, then reduced by the unified credit that shelters $15 million. Net estate tax owed: roughly $1.6 million.
Why the Taxable Estate Is Not the Final Tax
The taxable estate is the base, not the bill. The federal estate and gift tax system is unified, which means the executor has to add back any adjusted taxable gifts the decedent made during life — gifts above the annual exclusion of $19,000 per recipient for 2026.10Internal Revenue Service. Revenue Procedure 2025-32 That combined figure is what the rate schedule applies to.
The unified transfer tax rates are graduated, starting at 18% on the first $10,000 and climbing to 40% on amounts over $1 million.11Office of the Law Revision Counsel. 26 USC 2001 – Imposition and Rate of Tax In practice the lower brackets rarely matter. The unified credit wipes out the tax on the first $15 million of combined taxable estate and lifetime gifts, so the effective rate for most taxable estates is a flat 40% on everything above the exclusion.
Portability of an Unused Exclusion
When the first spouse dies without using the full $15 million exclusion — often because most of the estate passed to the surviving spouse under the marital deduction — the unused portion does not have to vanish. The executor can elect portability, which transfers the deceased spouse’s unused exclusion to the surviving spouse. The survivor then adds that amount to their own $15 million when they die.
Portability is not automatic. The executor has to file a complete Form 706, even if the estate owes no tax and would not otherwise need to file. Filing a timely return constitutes the election unless the executor affirmatively opts out.12eCFR. 26 CFR 20.2010-2 – Portability Provisions Applicable to Estate of a Decedent Survived by a Spouse For estates below the normal filing threshold, there is a simplified route: Form 706 can be filed within five years of death solely to make the portability election, with no user fee, under Rev. Proc. 2022-32.13Internal Revenue Service. Frequently Asked Questions on Estate Taxes
Skipping the election is one of the most expensive oversights in estate administration. A surviving spouse who could have inherited an extra $15 million in exclusion loses it entirely if nothing is ever filed.
Filing Form 706
The taxable estate is reported on Form 706, the United States Estate (and Generation-Skipping Transfer) Tax Return. Filing is required when the gross estate plus adjusted taxable gifts exceeds the basic exclusion amount, which is $15 million for 2026 decedents.14Internal Revenue Service. About Form 706, United States Estate (and Generation-Skipping Transfer) Tax Return
The return is due nine months after the date of death. The executor can request an automatic six-month extension by filing Form 4768 on or before the original due date. The extension only buys time to file. It does not extend the deadline to pay, and interest and penalties start accruing on any unpaid balance after the nine-month mark.15eCFR. 26 CFR 20.6081-1 – Extension of Time for Filing the Return The failure-to-file penalty is 5% of the unpaid tax for each month the return is late, up to 25%, with a separate failure-to-pay penalty running at 0.5% per month.16Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax
State Estate Taxes Are a Separate Problem
The federal taxable estate is only part of the picture. More than a dozen states and the District of Columbia impose their own estate taxes, often with far lower thresholds. Some begin taxing estates above $1 million, so an estate that owes nothing to the IRS can still owe substantial state tax. State death taxes paid are deductible on the federal return, but the deduction only partially offsets the combined load. Any executor should check whether the decedent was domiciled in, or owned real property in, a state that imposes its own estate or inheritance tax before assuming the federal number is the whole bill.