Massachusetts Estate Tax: Rates, Deductions, and Filing Deadlines

The Massachusetts estate tax applies to estates valued above $2 million, with graduated rates from 0.8% to 16% and a return due nine months after the date of death. It reaches every Massachusetts resident’s worldwide estate and any nonresident’s Massachusetts real estate or tangible personal property. A 2023 reform doubled the old $1 million threshold and added a $99,600 credit that ended the long-standing “cliff” where crossing the exemption by a dollar taxed the entire estate.

Who Has to File and Pay

Two groups fall within Chapter 65C: people who were Massachusetts residents when they died, and nonresidents who owned real estate or tangible personal property physically located in the state.¹ For residents, the tax covers the entire estate wherever the assets sit. For nonresidents, it reaches only the Massachusetts-based property.

For deaths in 2023 or later, the filing threshold is $2 million. If the gross estate plus adjusted taxable gifts made during life exceeds that amount, the executor must file a Massachusetts estate tax return.² The gift add-back captures lifetime transfers meant to shrink the estate below the line. Any gift exceeding the federal annual exclusion ($19,000 per recipient for 2026) counts.³

A return is still required in two situations that surprise people. First, when the gross estate is under $2 million on its own but the adjusted taxable gifts push the combined total over. Second, when the gross estate exceeds $2 million before backing out out-of-state property but falls below it after.⁴ In either case you file, even if the final tax is zero.

How Much the Tax Is

Massachusetts does not use a simple bracket the way income tax does. The tax equals what the old federal credit for state death taxes would have been under Internal Revenue Code Section 2011 as it existed on December 31, 2000, minus a $99,600 credit added in 2023.¹ The Department of Revenue publishes a lookup table with marginal rates that climb from 0.8% at the bottom to 16% on adjusted taxable estates above roughly $10 million.²

The starting figure is the “adjusted taxable estate”: the federal taxable estate (gross estate minus allowable federal deductions) minus $60,000. You look that number up in the table to find a base credit amount and the marginal rate on the excess. Add them for the preliminary tax, then subtract the $99,600 credit.⁴

That $99,600 figure exactly equals the tax the old table produces on a $2 million estate. So an estate of $2 million or less owes nothing, and estates above that pay tax effectively on the amount over $2 million rather than on the whole value.⁴ Before 2023, Massachusetts had one of the harshest estate tax cliffs in the country; an estate of $999,999 owed nothing while an estate of $1,000,001 owed tax on its entire value.

A Worked Example

A Massachusetts resident dies in 2026 with a federal taxable estate of $3 million. The adjusted taxable estate is $3,000,000 minus $60,000, or $2,940,000. That falls in the bracket starting at $2,540,000 with a base credit of $146,800 and a marginal rate of 8.8%. The excess over $2,540,000 is $400,000, and 8.8% of that is $35,200. The preliminary tax is $182,000. Subtract the $99,600 credit and the estate owes $82,400.

Deductions That Bring the Estate Down

Several deductions reduce the taxable estate before the rate table applies:

Debts and mortgages the decedent owed at death, including credit card balances and home loans.
Funeral expenses, legal fees, accounting services, and executor compensation, when properly documented.
Charitable bequests to qualifying organizations, deductible in full. For estates near or above $2 million, this can be a meaningful lever.
Property passing to a surviving spouse under the marital deduction, generally deductible in full and including property covered by a QTIP election.

Every asset is valued at fair market value as of the date of death. Real estate, closely held businesses, and collectibles typically call for professional appraisals.

Married Couples: No Portability, and What to Do About It

At the federal level, a surviving spouse can inherit the first spouse’s unused exemption through portability. Massachusetts does not offer this. If a couple does no planning and the first spouse leaves everything outright to the survivor, the first spouse’s $2 million Massachusetts exemption is lost. When the surviving spouse later dies with a combined estate above $2 million, the full tax applies.

The usual fix is a credit shelter trust, sometimes called a bypass trust. The first spouse’s estate funds the trust up to $2 million, with the surviving spouse retaining access to income and, in some cases, principal. Because the trust assets are not part of the surviving spouse’s estate at death, each spouse effectively uses their own exemption, sheltering up to $4 million combined.

The State-Only QTIP Election

The federal exemption for 2026 is $15 million while the Massachusetts exemption is $2 million, and that gap creates its own planning issue.⁵ Massachusetts allows a state-only QTIP election that operates independently of the federal election.⁶ An executor can treat certain property as qualifying terminable interest property for Massachusetts purposes without making the same election federally.

In practice, an executor can shelter $2 million through the credit shelter trust, direct additional assets into a QTIP trust to claim the Massachusetts marital deduction on those assets, and still trigger no federal tax because the total estate stays well under the federal exemption. The election is made on the Massachusetts return by the due date or any valid extension, and once made cannot be revoked.⁶ QTIP property included in the surviving spouse’s estate at death will then be subject to Massachusetts estate tax at that point.

Nonresidents Who Owned Property in Massachusetts

If a nonresident owned Massachusetts real estate or tangible personal property, the estate may owe Massachusetts tax even though the decedent lived elsewhere. The filing threshold is the same: the total worldwide estate plus adjusted taxable gifts must exceed $2 million.²

The tax is not charged on the full estate. Massachusetts applies an apportionment formula: the credit for state death taxes from the rate table, multiplied by the ratio of Massachusetts property value to the total federal gross estate.² If a nonresident’s total estate is $5 million and the Massachusetts property is worth $1 million, the estate pays 20% of what the full $5 million estate would owe. The executor files Form M-706 along with a Massachusetts Nonresident Decedent Affidavit (Form M-NRA).

Deadline, Return, and Extensions

The executor or administrator files Form M-706 with the Department of Revenue within nine months of the date of death.⁷ The return requires a full accounting of the decedent’s assets and liabilities, backed by appraisals and account statements.

An automatic six-month extension to file is available through Form M-4768, with a catch: at least 80% of the tax ultimately determined to be due must be paid within the original nine-month window.⁸ Miss that 80% mark and interest and penalties run from the original due date as though no extension existed.

This is where executors get caught. Estates with hard-to-value real estate or business interests may not know the final tax within nine months. Overestimating and claiming a refund is safer than underestimating and losing the extension.

What Happens if You File or Pay Late

Late filing and late payment carry separate penalties, and they can stack:

Late filing: 1% of the unpaid tax per month or partial month, up to 25%.⁹
Late payment interest: the federal short-term rate plus four percentage points, compounded daily. For the second quarter of 2026, that rate is 7%.¹⁰
Negligence or intentional disregard: an additional 20% of the underpayment if the Department of Revenue finds carelessness or deliberate noncompliance.⁹

Penalties, but not interest, can be waived or reduced if the executor shows reasonable cause. The test is whether the executor used the same degree of care an ordinary person in the same position would have used. The Department of Revenue presumes reasonable cause exists for at least part of a delay when the delay was directly caused by a death or serious illness that impaired the taxpayer’s ability to comply on time, and partial abatement is possible when only some of the delay is justified.¹¹

The Automatic Lien on Real Estate

On the date of death, Massachusetts places an automatic lien on every piece of real property in the estate. The lien secures any unpaid estate tax and lasts ten years unless released sooner.¹² You generally cannot sell or refinance while the lien is attached. Title companies flag it, and buyers walk.

To release the lien, the executor files Form M-706 with complete information about each parcel in Part 7 of the return. Once all estate tax is paid, the Department of Revenue issues a Certificate Releasing Massachusetts Estate Lien for each property.⁷ Incomplete Part 7 information is a common source of delay.

If you need to sell before filing the return, apply for an early release using Form M-4422. This form is available only before the M-706 due date or during a valid extension period.⁷ File the M-4422 as early as possible; processing takes time, and a delayed closing can put real pressure on the estate.

1
General Court of Massachusetts. Massachusetts General Laws Part I Title IX Chapter 65C Section 2A
2
Mass.gov. Massachusetts Estate Tax Guide
3
IRS. Frequently Asked Questions on Gift Taxes
4
Mass.gov. FAQs – New Estate Tax Changes
5
IRS. Whats New – Estate and Gift Tax
6
Massachusetts Department of Revenue. TIR 86-4 – MGL c 65C Massachusetts Estate Tax
7
Mass.gov. DOR Estate Tax Forms and Instructions
8
Mass.gov. Request an Extension to File and Pay Your Massachusetts Estate Tax
9
Mass.gov. Massachusetts Tax Penalty Rates
10
Mass.gov. TIR 26-2 – Interest Rate on Overpayments and Underpayments
11
Mass.gov. AP 633 – Guidelines for the Waiver and Abatement of Penalties
12
General Court of Massachusetts. Massachusetts General Laws Part I Title IX Chapter 65C Section 14