What the rule says
Massachusetts imposes a state estate tax under Mass. Gen. Laws ch. 65C on estates exceeding $2 million per individual — the lowest state estate tax threshold in the country. The framework has several distinctive features:
Lowest threshold nationally
The $2 million threshold (raised from $1 million in 2023) is significantly lower than: - Federal estate tax: ~$13.99 million per individual (2026, indexed) - New York: $7.16 million - Illinois: $4 million - Connecticut: $13.99 million (federal-conformed) - Most other state estate taxes
No portability
Like Illinois, Massachusetts does not recognize federal portability of unused exclusion between spouses. Each spouse's $2 million exclusion is used at that spouse's death; it cannot be transferred to the surviving spouse.
A Massachusetts married couple with $4 million in combined assets faces: - No federal estate tax at either death (well below federal threshold) - MA estate tax exposure at the surviving spouse's death if the entire amount remains, because the first-deceased spouse's $2 million exclusion is lost without bypass trust planning
Tax base after threshold
Unlike New York's cliff effect (where exceeding 105% of the threshold loses the entire exclusion), Massachusetts applies the tax progressively above the threshold. The top rate is 16%.
For an estate of $5 million, MA estate tax is approximately $390,000-$420,000 (specific calculation depends on tax tables).
What this means in practice
Massachusetts's combination of low threshold and no portability produces several distinctive scenarios:
- Moderate estates face MA tax that other states would not impose. A $3 million MA estate faces meaningful state tax; the same $3 million in NY (below the $7.16M threshold) faces no state estate tax. - Long-time MA homeowners often exceed the threshold. With Boston-area home values, retirement accounts, and other assets, families that don't consider themselves wealthy can find themselves above $2M. - Bypass trust planning is essential for MA married couples with $2M+ assets. A bypass trust at the first spouse's death preserves the $2 million exclusion that would otherwise be lost without portability. - No state-level adjustment for inflation. The MA threshold is $2 million in fixed dollars; it does not index automatically. Long-term inflation can push more estates into the tax over time.
How MA compares to other states
MA is unusual nationally for the combination of low threshold and no portability:
- Lower-threshold states with portability: Connecticut (federal-conformed exclusion with portability) - Lower-threshold states without portability: Massachusetts ($2M), Oregon ($1M), Illinois ($4M) - Higher-threshold states without portability: New York ($7.16M)
Massachusetts produces the most aggressive state estate tax exposure among major populous states.
Federal interaction
MA estate tax operates alongside federal estate tax:
- Estates below $2M face no estate tax of any kind. - Estates between $2M and $13.99M face MA estate tax but no federal estate tax. This is the gap where MA-specific planning matters most. - Estates above $13.99M face both MA and federal estate tax.
What you can do about it
For MA residents with substantial assets:
- Calculate MA estate tax exposure. The $2M threshold and no portability rule should drive planning calculations. - Use bypass trust planning. A bypass trust at the first spouse's death uses the $2M exclusion and removes assets from both spouses' estates. - Consider QTIP elections strategically. - Consider lifetime gifting. MA has no state-level gift tax. Lifetime gifts can reduce MA estate tax exposure. - Consider charitable bequests. Charitable transfers reduce the taxable estate. - Engage a MA estate tax advisor.
For high-net-worth MA residents considering relocation:
- Florida, Texas, NJ (no state estate tax). Domicile change can eliminate MA exposure if properly executed. - MA real estate remains taxable even for non-residents.
Who this affects most
MA's estate tax framework is most consequential for:
- Married MA residents with combined assets of $2M to $13.99M - Long-time MA homeowners whose property values, retirement accounts, and other assets push them above $2M - Estate planners coordinating MA-specific exposure with federal planning - Surviving spouses who would lose the deceased spouse's $2M MA exclusion without bypass trust planning
Massachusetts's low threshold + no portability framework produces among the most aggressive state estate tax exposure in the country. Bypass trust planning is the standard response, and the cost of failing to plan can be substantial relative to the modest threshold.