Massachusetts Estate Tax Calculator (2026 Exemption Limits & Inheritance Liabilities)

Massachusetts sets its estate tax exemption at $2,000,000, low enough that a family home in metro Boston, combined with a retirement account and modest savings, can push an otherwise unremarkable estate above the threshold without any of the wealth feeling especially large.

That $2,000,000 is also not a true exemption. Massachusetts runs the pre-2001 federal credit table across the whole estate and then subtracts a flat $99,600, a credit sized so the tax happens to reach zero at $2,000,000. One dollar past it and the tax is computed on the entire estate, not on the excess, which is why a $3,000,000 estate owes $82,400 rather than a few thousand.

Massachusetts is one of twelve states that still run a separate estate tax, and its $2,000,000 threshold is among the lowest of that group (only Oregon's exemption is set lower), which is why estate planning around this line gets attention in Massachusetts that residents of higher-exemption states rarely need.

The state does not levy a separate inheritance tax, so the estate-level bill described here is the only state death tax a beneficiary faces. Because Massachusetts real estate values have risen steadily for years, families who never considered themselves estate-tax candidates increasingly find their home equity alone is enough to cross the line.

The calculator starts from two numbers you enter: the gross estate at fair market value, and the marital, charitable, and administrative deductions the estate can claim. It subtracts the second from the first to get the net estate, then applies Massachusetts's own schedule to that figure. Nothing else feeds the result.

Massachusetts does not tax the excess over its exemption. Form M-706 applies the frozen pre-2001 federal state-death-tax credit table to the whole estate, less a $60,000 adjustment, and then subtracts a flat credit of $99,600. The credit is calibrated so a $2,000,000 estate lands at exactly zero, which is what makes $2,000,000 read as an exemption even though the statute never subtracts it.

1. Value the gross estate. Fair market value at the date of death of all real property, business interests, securities, cash, and life insurance proceeds the decedent owned.
2. Subtract allowable deductions. Debts, administrative expenses, qualifying charitable bequests, and the unlimited marital deduction come off the gross figure.
3. Subtract $60,000 to reach the adjusted taxable estate the credit table is indexed against.
4. Run the credit table. Its twenty-one graduated steps start at 0.8% just above $40,000 and reach 16% above $10,040,000, applied to the adjusted taxable estate slice by slice.
5. Subtract the $99,600 credit. A negative result is treated as zero.
6. Subtract the tax from the net estate to get what beneficiaries receive.

Because the table runs against the whole estate rather than the excess, the tax climbs faster just past $2,000,000 than a bracket-on-excess reading would predict: a $3,000,000 estate owes $82,400, an effective rate of 2.75%, not 0.8% of the first slice above the threshold.

That is the entire computation. The calculator does not carry over a deceased spouse's unused exemption, add back lifetime taxable gifts, apply the generation-skipping transfer tax, discount closely held interests, or figure the separate federal return. Those sit under "What This Does Not Account For" below, not in the math above.

1. Start with the gross estate. This example uses a $5,000,000 gross estate: the fair market value of all property, business interests, equities, cash, and life insurance the decedent owned at death, before deductions.
2. Apply the credit-table schedule to the whole estate, not just the excess. Massachusetts (Form M-706) runs the pre-2001 federal state-death-tax-credit table against an "adjusted taxable estate" of $5,000,000 − $60,000 = $4,940,000. That falls in the table's $4,040,000-$5,040,000 bracket: $290,800 + 11.2% × ($4,940,000 − $4,040,000) = $391,600.
3. Subtract the flat $99,600 credit. The credit is calibrated so that an estate at exactly the $2,000,000 exemption owes $0 ($1,940,000 adjusted taxable estate lands on a table value of exactly $99,600). $391,600 − $99,600 = $292,000.
4. Net estate distributed to heirs. $292,000 in tax leaves $4,708,000 ($5,000,000 minus $292,000) to beneficiaries.
5. Why this isn't "excess × 16%." A naive flat-rate calculation on the $3,000,000 above the exemption would suggest $480,000; the real table-and-credit mechanism produces $292,000 instead, because the credit table is graduated and applies to the whole estate before the flat credit is subtracted.
6. What this leaves out. This is Massachusetts's state-level computation only; federal estate tax is assessed separately under IRC § 2010.

The credit-table mechanism has a consequence that surprises almost everyone who reads Massachusetts's rate schedule from the top: the entry rate at the threshold is not the table's lowest rate. Walking the sweep across $2,000,000 is the clearest way to see it.

The threshold walk. At a gross estate of $1,990,000 the engine returns $0.00. At exactly $2,000,000 it still returns $0.00, with the full $2,000,000.00 passing to heirs. At $2,001,000, one thousand dollars later, it returns $72.00. At $2,010,000 it returns $720.00. That first $1,000 over the line therefore costs $72.00, a marginal rate of 7.2%, because the credit table works on an adjusted taxable estate of the whole estate less $60,000, and $1,941,000 already sits in the table's 7.2% band. The table's 0.8% opening rate applies to adjusted taxable estates between $40,000 and $90,000 and is unreachable by any estate that owes Massachusetts anything.

The marginal cost of the next unit. Just above the threshold each $1,000 costs $72.00. By a $3,000,000 estate the engine reports $82,400.00, an effective 2.75%; by $5,000,000, $292,000.00 at 5.84%; by $15,000,000, $1,767,200.00 at 11.78%. The effective rate rises continuously because the graduated table applies to the whole estate, not to a slice of it.

The reverse question. The largest estate that owes Massachusetts nothing is exactly $2,000,000, and deductions extend that ceiling because the calculator subtracts them from gross before the table is applied. A $5,000,000 gross estate with $1,000,000 of allowable deductions computes to $180,800.00 rather than the $292,000.00 it owes with none, so that million dollars of deduction is worth $111,200.00, an effective 11.12% saving rather than the 16% top rate a quick estimate would suggest.

Right method against wrong method, priced. Treating $2,000,000 as an exemption and applying a flat rate to the excess is the standard error. On a $3,000,000 estate, 16% of the $1,000,000 excess gives $160,000 against the engine's $82,400.00, an overstatement of $77,600.00. Nearer the threshold the same method understates instead: on a $2,010,000 estate it gives $1,600 against the computed $720.00. There is no single flat rate that reproduces the credit table at more than one estate size.

What the engine does and does not carry. It applies the pre-2001 credit table to the whole estate and subtracts the flat $99,600 credit, which is calculateCreditTableEstateTax in the state tax primitive. It does not model the Massachusetts real-property apportionment for non-resident decedents, and it does not test whether the estate qualifies for any elective valuation. It also computes an estate tax only: Massachusetts levies no inheritance tax, so unlike Maryland the figure here is the whole state bill.

• Portability of a deceased spouse's unused exemption. Most states with an estate tax, including this one, do not allow it at the state level, and the calculator does not apply it in either direction.
• Lifetime taxable gifts added back into the taxable estate, and any QTIP election, credit shelter trust, or state QTIP decoupling that would change what the taxable estate actually is.
• Valuation discounts for minority or non-marketable interests in closely held entities. Enter the discounted value yourself if the appraisal supports one.
• Federal generation-skipping transfer (GST) tax under IRC Chapter 13.
• Ancillary probate requirements for real property situated in other jurisdictions.
• Complex liquidity discounts for minority non-voting family business entities.
• State-specific inheritance taxes levied directly on beneficiaries (e.g. PA, NJ, MD, KY, NE).

• Assuming State Exemption Matches Federal: Forgetting that states like Oregon ($1.0M) and Massachusetts ($2.0M) tax estates far below the federal threshold.
• The "Cliff" Effect in Specific States: Failing to recognize that states like New York eliminate the exemption entirely if the estate exceeds 105% of the threshold.
• Out-of-State Real Property Exposure: Holding real estate in states with active estate taxes exposes non-resident estates to proportional state estate taxes.
• Failing to Fund Revocable Living Trusts: Assets held outside trust structures are subjected to public probate proceedings and statutory executor fees.

• Massachusetts Department of Revenue: Estate Tax Guidance (2026). mass.gov/orgs/massachusetts-department-of-revenue