The Massachusetts estate tax applies when a resident dies with a taxable estate over $2 million, and the tax is calculated on a graduated rate table that reaches 16%, then reduced by a flat $99,600 credit. That $2 million threshold, in place for deaths on or after January 1, 2023, replaced a much harsher $1 million system that taxed estates from the first dollar. The state gap with the federal exemption of $15 million for 2026 means most Massachusetts estate planning today is a state-level problem, not a federal one.
How the Tax Is Calculated
Massachusetts does not use a simple percentage bracket. The taxable estate is reduced by $60,000 to produce the “adjusted taxable estate,” which is then run through a rate table with marginal rates from 0.8% on the first $40,000 above the base up to 16% on amounts above roughly $10 million. That produces a tentative tax figure. The $99,600 credit is subtracted from that figure to reach the actual tax owed.1Mass.gov. Massachusetts Estate Tax Guide
Here is what that looks like on a $2,500,000 estate. Subtracting $60,000 gives an adjusted taxable estate of $2,440,000. The rate table yields a tentative tax of $138,800. After the $99,600 credit, the actual Massachusetts estate tax comes to $39,200. Under the old rules the same estate would have owed the full $138,800.1Mass.gov. Massachusetts Estate Tax Guide
Estates at or below $2 million owe nothing, because the credit fully offsets the computed tax. Above $2 million, the credit still reduces the bill but no longer wipes it out.2Mass.gov. FAQs: New Estate Tax Changes
What Counts in the Estate
The taxable estate includes everything the decedent owned at death at fair market value on that date: real property, bank accounts, investment accounts, retirement funds, business interests, and personal property. Accurate appraisals matter, especially for real estate and closely held businesses, because the Department of Revenue can challenge low valuations.
Several deductions shrink the number. Debts and mortgages, funeral and administration expenses, and charitable bequests all come out of the taxable estate. The biggest one for married couples is the unlimited marital deduction: assets passing to a surviving spouse transfer entirely free of Massachusetts estate tax.3Massachusetts Department of Revenue. Directive 95-1: The Massachusetts Unlimited Marital Deduction
The marital deduction defers tax rather than eliminating it. Whatever the surviving spouse inherits becomes part of their own estate when they later die, which is why spousal planning here takes more thought than at the federal level.
Filing Form M-706 and the Nine-Month Deadline
The executor must file Form M-706, the Massachusetts Estate Tax Return, if the gross estate plus adjusted taxable gifts exceeds $2 million. The return and any tax payment are due nine months after the date of death.4Mass.gov. Instructions for Massachusetts Estate Tax Return Form M-706
A six-month extension to file is available by submitting Form M-4768 before the original due date. The trap: the executor must pay at least 80% of the estimated tax by the original deadline. Miss that, and the extension is voided with penalties applied retroactively.5Mass.gov. Form M-4768 Massachusetts Estate Tax Extension Application
Late filing runs 1% of the tax due per month, capped at 25%. Late payment adds another 1% per month, also capped at 25%. Interest accrues on top of both at a rate that changes quarterly. Ignoring the deadline for a full year can add 24% in penalties alone before interest.1Mass.gov. Massachusetts Estate Tax Guide
Non-Residents Who Own Massachusetts Property
You don’t have to live here to owe Massachusetts estate tax. Non-residents who own real property or tangible personal property in the state must file if their total worldwide estate exceeds $2 million. The tax is prorated to the Massachusetts share, based on the ratio of the Massachusetts property’s value to the total federal gross estate.1Mass.gov. Massachusetts Estate Tax Guide
A non-resident executor also files Form M-NRA, the Nonresident Decedent Affidavit, along with Form M-706. Intangible property like stocks, bonds, and mutual fund shares is generally not subject to Massachusetts estate tax for non-residents, even when the brokerage account sits at a Massachusetts institution. Exposure is limited to real estate and physical assets located in the state.
Why Married Couples Need a Plan: No State Portability
Federal law lets a surviving spouse inherit the deceased spouse’s unused estate tax exemption through portability, elected on a federal Form 706. Massachusetts does not offer this. When the first spouse dies and everything passes to the surviving spouse under the marital deduction, the first spouse’s $2 million exemption disappears. The surviving spouse still has only their own $2 million.
For a couple with a combined estate of $4 million, that is the difference between paying zero state tax if both exemptions are used and paying tax on roughly $2 million if only one is. The absence of state portability is why a credit shelter trust remains a workhorse tool for Massachusetts couples.
Credit Shelter Trusts
A credit shelter trust, sometimes called a bypass trust, captures the first spouse’s $2 million exemption at death instead of letting it vanish. When the first spouse dies, up to $2 million flows into an irrevocable trust rather than passing outright to the survivor. The surviving spouse can still benefit from the trust during their lifetime, receiving income and in some cases principal depending on how the trust is drafted, but the assets inside are not counted in the survivor’s estate at their later death.
Take a couple with $4 million in combined assets. Without a credit shelter trust, the first spouse’s death passes everything to the survivor tax-free, leaving a $4 million estate covered by only a $2 million exemption. With the trust, $2 million goes into the bypass structure (sheltered by the first spouse’s exemption) and the survivor’s taxable estate stays at $2 million, covered by their own exemption. The result is zero Massachusetts estate tax across both deaths instead of a bill that could reach roughly $100,000 or more.
Couples whose combined estates fall below $2 million generally don’t need this structure. Those between $2 million and $4 million benefit the most. Above $4 million, the trust still helps but won’t zero out the tax on its own.
Gifting to Shrink the Estate
Massachusetts imposes no gift tax, which creates a clean planning path. Lifetime gifts reduce the estate that will eventually be measured against the $2 million threshold. The federal annual gift tax exclusion for 2026 is $19,000 per recipient, so a married couple can give $38,000 per year to each child, grandchild, or other beneficiary without filing a federal gift tax return or touching any lifetime exemption.6Internal Revenue Service. What’s New – Estate and Gift Tax
One nuance to keep straight: Massachusetts requires the estate tax return to account for adjusted taxable gifts, so if the gross estate plus those gifts exceeds $2 million, a return must be filed even when the gross estate alone falls under the threshold. Annual exclusion gifts are not “adjusted taxable gifts” under the federal system and don’t count toward this total. Only gifts above the annual exclusion that consume part of the lifetime exemption do.
For estates hovering near the threshold, a disciplined multi-year gifting program can move an estate below $2 million entirely. A couple gifting $38,000 per year to each of three children removes $114,000 annually with no tax consequences.
Step-Up in Basis Cuts the Other Way
Inherited property gets a new federal tax basis equal to its fair market value on the date of death. That step-up wipes out unrealized capital gains that built up during the decedent’s lifetime.7Office of the Law Revision Counsel. 26 U.S. Code 1014 – Basis of Property Acquired From a Decedent
The effect can be large. A house bought for $200,000 and worth $800,000 at death passes to the heir with an $800,000 basis. Selling right away produces no capital gain. Without the step-up, the heir would owe capital gains tax on $600,000 of appreciation.8Internal Revenue Service. Gifts and Inheritances
This creates tension with gifting. Assets given during life carry the donor’s original basis, so the recipient inherits the built-in gain. Assets transferred at death get the fresh basis. For highly appreciated property, holding until death and letting the heir take the clean basis can beat gifting, even though holding keeps the estate larger for Massachusetts purposes. The right answer turns on the specific numbers: capital gains tax saved against estate tax incurred.
Life Insurance and Estate Liquidity
Nine months is a short runway when most of an estate’s value is locked up in real property or a family business. Heirs can end up selling assets fast, often at a discount, to cover the state tax bill.
Life insurance can supply the cash, but structure matters. If the decedent owned the policy or held any control over it at death, the full death benefit is pulled into the taxable estate and can actually raise the tax. The fix is an irrevocable life insurance trust (ILIT) that owns the policy, pays the premiums, and receives the death benefit outside the estate. Proceeds can then be used to pay estate taxes or provide for beneficiaries without inflating the taxable estate.
Timing has a hard edge. If an existing policy is transferred into an ILIT, the insured must survive at least three years after the transfer, or the proceeds get pulled back into the estate as if the transfer never happened. Having the trust purchase a new policy from the outset avoids that risk.
Planning Priorities by Estate Size
- Under $2 million: no Massachusetts estate tax is owed. The task is making sure the total, including life insurance proceeds, actually stays under the threshold. A simple will or revocable trust handles distribution.
- $2 million to $4 million: prime territory for credit shelter trust planning between spouses. A well-drafted plan can often eliminate the state tax entirely, and annual gifting can move the needle further.
- $4 million to $10 million: credit shelter trusts remain essential but won’t zero out the bill. Layer in gifting, charitable bequests, and consider an ILIT for liquidity. Effective tax rates in this range run roughly 8% to 14% on amounts above the exemption.
- Over $10 million: both state and potentially federal taxes are in play, though the $15 million federal exemption still shelters most estates at this level. Charitable remainder trusts, family limited partnerships, and generation-skipping trusts enter the conversation, and professional guidance is not optional.
The $99,600 credit softened the blow, but Massachusetts still taxes estates starting well below the median home price in many of its communities. A family home in Greater Boston plus retirement accounts and a life insurance policy can push an estate past $2 million without much effort, which makes the state estate tax a middle-class concern as much as a wealthy-family one.