IRC 2051: Gross Estate, Deductions, and Portability

The taxable estate is defined in Internal Revenue Code Section 2051 as the gross estate minus all deductions allowed under the estate tax rules. That single subtraction produces the figure the federal estate tax is calculated on. For a person dying in 2026, only the portion of the taxable estate (combined with lifetime taxable gifts) above the $15 million basic exclusion amount is exposed to the top rate of 40%.¹²

So the definition is a subtraction, but each side of that subtraction has its own rules. What follows walks through both: what gets pulled into the gross estate, what comes back out as a deduction, and how the resulting taxable estate feeds into the tax the estate actually owes.

What Goes Into the Gross Estate

The gross estate is the starting number. It includes the fair market value of everything the decedent had an interest in at death: real estate, bank accounts, investment portfolios, business interests, vehicles, personal property, and intangible assets like patents or royalties. For a U.S. citizen or resident, location does not matter. Property situated anywhere in the world counts.

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 which spouse paid for it. Every other joint ownership arrangement starts from the opposite presumption. The IRS assumes the full value belongs to the decedent’s estate, and the executor can reduce that only by proving the surviving co-owner contributed their own money toward the purchase. Whatever percentage the survivor independently funded gets excluded.

Life Insurance

Life insurance proceeds are pulled into the gross estate in two situations: when the policy pays directly to the estate, or when the decedent held “incidents of ownership” in the policy at death. That phrase covers more than most people expect. It includes the power to change the beneficiary, cancel or surrender the policy, borrow against its cash value, and any reversionary interest worth more than 5% of the policy’s value.³

Someone who bought a $2 million policy, named their children as beneficiaries, and assumed the proceeds would sit outside the estate is wrong if they still owned the policy at death. An irrevocable life insurance trust can move the policy out, but only if the transfer happened more than three years before death.

Transfers With Strings Attached

The gross estate also captures property the decedent gave away during life if they kept too much control. A parent who transferred a rental property to a child but continued collecting the rent still has that property in their gross estate. The same is true for property in a trust if the decedent retained the right to income, the power to decide who benefits, or the ability to revoke or amend the arrangement.⁴

A less obvious trigger: keeping the right to vote shares of stock in a controlled corporation (one in which the decedent owned or could vote at least 20% of total voting power) counts as retaining enjoyment of the transferred property.⁴

Annuities, including certain retirement accounts, round out the gross estate to the extent attributable to the decedent’s contributions.

Valuing the Assets

The default is fair market value on the date of death. The executor has one alternative: electing to value everything as of six months after the date of death.⁵

The alternate valuation date exists for estates that lost value between death and the six-month mark, such as a market crash or a sharp drop in real estate values. There is a condition: the election is only available if it actually reduces both the gross estate value and the estate tax liability. The executor cannot cherry-pick which assets get the alternate date; the election applies to everything. Any asset sold, distributed, or otherwise disposed of within that six-month window is valued on the date it left the estate.⁵

Deductions That Turn the Gross Estate Into the Taxable Estate

Once the gross estate is settled, the deductions do the rest of the work in Section 2051. Each is a specific statutory allowance, and missing any of them means overpaying.

Administration Expenses and Debts

The estate can deduct the costs of settling itself: executor commissions, attorney fees, accounting fees, court costs, and appraisal fees. Funeral expenses come off as well, including reasonable burial costs and perpetual care of the gravesite. The decedent’s outstanding debts (mortgages, credit card balances, medical bills, personal loans) reduce the gross estate too, provided they were owed for real value received rather than disguised gifts.

A ceiling applies: the deduction cannot exceed what the law of the state where the estate is being administered would allow. If state law caps executor commissions at a certain percentage, the federal deduction stops there. The expenses must be genuine, not inflated fees used as a conduit for transferring wealth to family.⁶

Losses During Administration

If estate property is damaged or destroyed by fire, storm, or another casualty, or stolen during administration, the uninsured portion of the loss is deductible. The loss has to occur before the property is distributed to beneficiaries; once it’s in their hands, it’s their loss. The estate must also choose: deduct the loss on the estate tax return or on the estate’s income tax return, not both.⁷

Charitable Deduction

Property left to a qualifying charity comes out of the gross estate 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.

Transfers that split benefits between charity and private beneficiaries face tighter rules. For the charitable portion of a split-interest gift to qualify, the remainder interest must be held in a charitable remainder annuity trust, a charitable remainder unitrust, or a pooled income fund. Partial interests outside those approved structures are not deductible.⁸

Marital Deduction

For married decedents, this is typically the largest single reduction. The estate can deduct 100% of qualifying property passing to a surviving spouse who is a U.S. citizen. There is no dollar limit. The effect is to defer all estate tax until the second spouse dies.

The main restriction is the “terminable interest” rule: property that passes to the surviving spouse but will end at some point and then pass to someone else generally does not qualify. The important exception is Qualified Terminable Interest Property, or QTIP. A QTIP trust qualifies for the marital deduction if the surviving spouse receives all the income at least annually and no one can redirect any part of the trust property to another beneficiary while the spouse is alive. The executor must affirmatively elect QTIP treatment on the estate tax return.

Non-Citizen Surviving Spouse

If the surviving spouse is not a U.S. citizen, the unlimited marital deduction is not available for a direct bequest. To qualify, the property must pass through a Qualified Domestic Trust (QDOT). A QDOT requires 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.⁹ Missing this requirement can leave millions in property fully taxable in the first estate.

From Taxable Estate to Tax Owed

The taxable estate itself is straightforward: gross estate minus deductions. But the taxable estate does not directly equal the tax bill, because the estate and gift tax system is unified.¹

The executor adds back any adjusted taxable gifts the decedent made during life (gifts above the annual exclusion, which is $19,000 per recipient for 2026). The rate schedule applies to that combined figure.¹⁰

The rates are graduated, starting at 18% on the first $10,000 and climbing to 40% on amounts over $1 million.¹¹ In practice, the lower brackets rarely matter. The unified credit wipes out tax on the first $15 million of combined taxable estate and lifetime gifts, so the effective rate for most taxable estates is 40% on everything above the exclusion.²

A simplified example. A decedent dies in 2026 with a gross estate of $20 million, claims $2 million in deductions, and made $1 million in adjusted taxable gifts during life. The taxable estate is $18 million. Adding the $1 million in lifetime gifts produces a combined transfer of $19 million. The tentative tax on $19 million comes from the rate schedule, then the unified credit shelters $15 million of it. The net estate tax owed in this scenario is roughly $1.6 million.

Portability for a Surviving Spouse

When the first spouse dies and does not use the entire $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 disappear. The executor can elect portability, which transfers the deceased spouse’s unused exclusion, or DSUE, to the surviving spouse. The survivor adds it to their own exclusion when they die.

Portability is not automatic. The executor must file a complete Form 706, even if the estate is too small to owe tax or otherwise require filing. A timely-filed estate tax return constitutes the portability election unless the executor affirmatively opts out.¹²

Where the Taxable Estate Gets Reported

The taxable estate calculation lives 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 for the year of death, which is $15 million for 2026.¹³¹⁰

The return is due nine months after the date of death. Form 4768, filed on or before the original due date, gets an automatic six-month extension of time to file. It does not extend the deadline to pay; interest and penalties begin accruing on any unpaid balance after nine months.¹⁴

A Note on State Estate Taxes

The Section 2051 calculation is federal. More than a dozen states and the District of Columbia impose their own estate taxes, often with significantly lower thresholds; some begin taxing estates above $1 million. An estate that owes nothing federally can still owe substantial state estate tax. State death taxes paid by the estate are deductible on the federal return, but only partially offset the combined burden. 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.

1
Office of the Law Revision Counsel. 26 USC 2051 – Definition of Taxable Estate
2
Office of the Law Revision Counsel. 26 USC 2010 – Unified Credit Against Estate Tax
3
Office of the Law Revision Counsel. 26 USC 2042 – Proceeds of Life Insurance
4
Office of the Law Revision Counsel. 26 USC 2036 – Transfers With Retained Life Estate
5
Office of the Law Revision Counsel. 26 USC 2032 – Alternate Valuation
6
eCFR. 26 CFR 20.2053-1 – Deductions for Expenses, Indebtedness, and Taxes; In General
7
eCFR. 26 CFR 20.2054-1 – Deduction for Losses
8
Office of the Law Revision Counsel. 26 USC 2055 – Transfers for Public, Charitable, and Religious Uses
9
Office of the Law Revision Counsel. 26 USC 2056A – Qualified Domestic Trust
10
Internal Revenue Service. Revenue Procedure 2025-32
11
Office of the Law Revision Counsel. 26 USC 2001 – Imposition and Rate of Tax
12
eCFR. 26 CFR 20.2010-2 – Portability Provisions Applicable to Estate of a Decedent Survived by a Spouse
13
Internal Revenue Service. About Form 706, United States Estate (and Generation-Skipping Transfer) Tax Return
14
eCFR. 26 CFR 20.6081-1 – Extension of Time for Filing the Return