Roth conversion taxes in Massachusetts (2026)
By Mario Bailey · Published · Last reviewed
Massachusetts taxes Roth conversions as ordinary income at graduated rates up to 9%. A conversion adds to your state taxable income in the year you convert, on top of federal tax. The table below shows the computed Massachusetts tax on a $50,000 conversion at three baseline income levels, using 2026 rates.
Computed example: $50,000 conversion
State tax only (federal not included), age 66, standard deduction, no other state adjustments. Computed with the same functions the calculator uses.
| Filing status | Baseline income | State tax without conversion | With $50,000 conversion | Tax on the conversion | Effective rate |
|---|---|---|---|---|---|
| Single | $40,000 | $1,780 | $4,280 | $2,500 | 5.0% |
| Single | $80,000 | $3,780 | $6,280 | $2,500 | 5.0% |
| Single | $150,000 | $7,280 | $9,780 | $2,500 | 5.0% |
| Married filing jointly | $40,000 | $1,560 | $4,060 | $2,500 | 5.0% |
| Married filing jointly | $80,000 | $3,560 | $6,060 | $2,500 | 5.0% |
| Married filing jointly | $150,000 | $7,060 | $9,560 | $2,500 | 5.0% |
Social Security and retirement income
Massachusetts does not tax Social Security benefits. A conversion can still raise the federally taxable share of your benefits through the provisional income formula.
The 4% surtax threshold for 2026 is $1,107,750 (inflation-adjusted). Income above that threshold is taxed at 9% total (5% base + 4% surtax). All four filing statuses use the same threshold. MA does not provide a standard deduction; personal exemptions are used instead ($4,400 single/MFS, $6,800 HoH, $8,800 MFJ). An additional $700 exemption applies for taxpayers age 65+ but is not modeled here.
FAQ
Does Massachusetts tax Roth conversions?
Yes. Massachusetts taxes Roth conversions as ordinary income at graduated rates up to 9%. Federal tax applies on top.
Does Massachusetts tax Social Security benefits?
No. Social Security benefits are not subject to Massachusetts income tax.
What is the top Massachusetts rate on a conversion in 2026?
9% at the highest marginal rate.
Model your Massachusetts conversion in the calculator
Rate data source: Massachusetts Department of Revenue, Massachusetts Tax Rates (mass.gov); 4% surtax threshold $1,107,750 for 2026 per Fair Share Amendment (Article 44)