Estate tax apportionment is the set of rules that decides which beneficiaries actually bear the federal estate tax bill after someone dies. The executor writes the check to the IRS, but the money comes out of specific inheritances, and who loses what depends on three things in this order: what the will or trust says, what federal law lets the executor recover from non-probate recipients, and what the state’s default statute does when the documents are silent. For 2026 the federal exemption is $15,000,000 per person, so only estates above that threshold face the question at all.1Office of the Law Revision Counsel. 26 USC 2010 – Unified Credit Against Estate Tax
Above that line, the top federal rate is 40%, applied on a progressive scale to the portion of the estate exceeding the exemption. Married couples can effectively double the exemption through portability, but only if the executor of the first spouse’s estate files Form 706 and elects portability, even when no tax is owed.1Office of the Law Revision Counsel. 26 USC 2010 – Unified Credit Against Estate Tax
What the Will or Trust Says Controls
The most reliable way to decide who pays estate tax is a tax apportionment clause in the will or revocable trust. The executor is legally bound to follow whatever the document says, and a clear direction overrides state defaults.
A common drafting choice is “burden on the residue,” which tells the executor to pay all estate taxes from the residuary estate before dividing what’s left. This protects specific bequests, like a $100,000 gift to a grandchild or a piece of property left to a sibling, from being reduced by tax. The tradeoff can be severe. An estate worth $20 million with $2 million in specific bequests and a $2 million tax bill leaves the residuary heir absorbing the entire tax from their share.2The CPA Journal. Wills: Importance of Tax Apportionment Clause
A better-drafted clause can direct certain beneficiaries to pay a proportionate share, spread the tax across all recipients, or exempt specific gifts while loading the burden onto others. Vague language causes expensive fights. A clause reading “all taxes shall be paid from my estate” without specifying which assets fund the payment can be read multiple ways, and probate courts see litigation over exactly that ambiguity.
What Happens When the Document Is Silent
If the will says nothing about taxes, or if there is no will at all, the state’s default apportionment statute controls. Most states apply some form of equitable apportionment: each beneficiary pays a share of the tax proportional to the value of what they receive. Inherit 30% of the taxable estate, bear roughly 30% of the tax.
Many states have adopted a version of the Uniform Estate Tax Apportionment Act, which standardizes that pro-rata calculation. Each beneficiary’s inheritance is divided by the total value of the taxable estate, and the resulting percentage is applied to the total tax due.
Equitable apportionment replaced an older common-law rule that loaded the entire tax onto the residuary estate. Under the old approach, a beneficiary receiving a multimillion-dollar specific bequest paid nothing while the residuary heir absorbed the full hit. A minority of jurisdictions still default to that rule, which is why silence in the document is not a safe choice.
Reaching Beneficiaries Who Received Non-Probate Assets
Much of what gets taxed in an estate never passes through probate. Life insurance, retirement accounts, jointly held property, and assets in revocable trusts all count toward the gross estate but transfer directly to named beneficiaries. Without a mechanism to reach them, probate beneficiaries would pay tax on wealth they never received. Federal law gives the executor several recovery rights.
Life Insurance
Under IRC § 2206, the executor can recover a proportionate share of the estate tax from anyone who received life insurance proceeds on the deceased’s life, unless the will directs otherwise. The recovery tracks the ratio of insurance proceeds to the total taxable estate. Proceeds qualifying for the marital deduction are excluded from the calculation.3Office of the Law Revision Counsel. 26 USC 2206 – Liability of Recipients of Proceeds of Life Insurance Policies
Powers of Appointment, QTIP Trusts, and Retained Interests
IRC § 2207 gives the executor the same recovery right against anyone who received property through a general power of appointment held by the deceased.4Office of the Law Revision Counsel. 26 USC 2207 – Liability of Recipient of Property Over Which Decedent Had Power of Appointment IRC § 2207A covers Qualified Terminable Interest Property (QTIP) trusts, where a surviving spouse received income during life and the trust assets are pulled into that spouse’s estate at death; the estate can recover the incremental tax caused by those trust assets from whoever ends up with the QTIP property.5Office of the Law Revision Counsel. 26 USC 2207A – Right of Recovery in the Case of Certain Marital Deduction Property IRC § 2207B applies when the deceased retained a life estate or similar interest in transferred property, such as living in a home already given to the children. The corresponding tax can be recovered from whoever receives the property.6Office of the Law Revision Counsel. 26 USC 2207B – Right of Recovery Where Decedent Retained Interest
Retirement Accounts
Beneficiaries of IRAs and 401(k)s face two layers of tax. The account balance is included in the gross estate, and the beneficiary owes income tax on distributions. IRC § 691(c) softens the overlap by letting the beneficiary claim an income tax deduction for the estate tax attributable to the retirement account. The deduction does not erase the income tax, but it prevents the same dollars from being fully taxed twice.7Office of the Law Revision Counsel. 26 USC 691 – Recipients of Income in Respect of Decedents The calculation compares the estate tax actually paid against what it would have been without the retirement account in the estate; skipping the deduction means overpaying income tax, sometimes by a substantial amount.
Spouses and Charities Are Carved Out
Assets passing to a surviving spouse are deductible from the gross estate under the marital deduction, with no dollar limit.8Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse Bequests to qualified charities are similarly deductible.9Office of the Law Revision Counsel. 26 USC 2055 – Transfers for Public, Charitable, and Religious Uses Because these transfers generate no estate tax, the recipients generally bear none of the burden. Under equitable apportionment they drop out of the pro-rata calculation entirely.
Consider an estate where 60% of the value goes to a surviving spouse tax-free and 40% goes to children. Only the taxable portion generates the tax, so only the children pay. A well-drafted tax clause makes this explicit, and most state default statutes reach the same result by carving deduction-eligible property out of the formula.
Generation-Skipping Transfer Tax Has Its Own Rules
When assets skip a generation, such as a grandparent leaving money directly to a grandchild, a separate generation-skipping transfer (GST) tax can apply on top of the estate tax. For direct transfers from a trust, the trustee pays. For distributions from a trust to a skip person, the recipient pays. For direct gifts outside a trust, the transferor pays.10Office of the Law Revision Counsel. 26 USC 2603 – Liability for Tax
By default the GST tax is charged against the transferred property itself. A will or trust can override that default, but courts generally require the document to reference the GST tax by name. A generic clause covering “all taxes” may not be enough to redirect the GST tax burden, depending on the jurisdiction.
Personal Liability If the Tax Goes Unpaid
Apportionment is not an academic exercise. Both beneficiaries and executors carry real personal exposure.
Under IRC § 6324(a)(2), anyone who received property included in the gross estate, including a surviving spouse, trust beneficiary, or life insurance recipient, can be held personally liable for unpaid estate tax up to the value of the property they received at the date of death.11Office of the Law Revision Counsel. 26 USC 6324 – Special Liens for Estate and Gift Taxes
Executors carry a separate risk. If an executor distributes estate assets to beneficiaries or other creditors before satisfying the government’s tax claim, the executor becomes personally liable for the unpaid tax to the extent of those distributions.12Office of the Law Revision Counsel. 31 USC 3713 – Priority of Government Claims Experienced executors wait for the IRS closing letter before making final distributions. An executor can also request a formal discharge from personal liability by filing Form 5495. The discharge takes effect nine months after the IRS receives the request, or earlier if the executor pays any amount the IRS determines is still owed.13Internal Revenue Service. Request for Discharge From Personal Liability Under Internal Revenue Code Section 2204 or 6905
State Death Taxes Follow Their Own Apportionment
Federal apportionment does not settle the state tax picture. Roughly a dozen states and the District of Columbia impose their own estate taxes, some with exemptions as low as $1 million, and a handful of states levy an inheritance tax instead. One state imposes both.
The difference matters for apportionment. An estate tax is calculated on the total estate value and paid before distribution, like the federal tax. An inheritance tax is calculated based on what each individual beneficiary receives, and the rate typically depends on the recipient’s relationship to the deceased. Spouses and children usually pay little or nothing; distant relatives and unrelated beneficiaries can face rates of 15% or more. When both types of tax apply, the apportionment clause needs to address each one separately, or the default rules for each may produce conflicting results.
State apportionment rules do not always mirror federal law. Some states use their own version of equitable apportionment; others still default to the older burden-on-the-residue rule. An estate plan that works cleanly for federal purposes can produce unintended results at the state level if the drafter ignored the state regime. Executors handling estates in states with their own death taxes should verify the applicable state rules rather than assuming the federal framework controls.