How your Massachusetts paycheck is calculated
Massachusetts withholding
Circular M subtracts Social Security and Medicare withheld (until $2,000 has been subtracted in the year) and your exemption amount ($169 biweekly for one exemption; $38 per exemption plus $131 for more), annualizes the result, applies 5% (9% on the part above $1,107,750, the 2026 surtax threshold), and divides by pay periods. Heads of household subtract $4.62 per biweekly paycheck and each blind person $4.23. Because the FICA subtraction stops once $2,000 is reached, we show the yearly average per paycheck; your first paychecks of the year will be slightly lower.
Paid Family & Medical Leave
In 2026 employers may withhold up to 0.18% (family) + 0.28% (medical) = 0.46% of eligible wages, capped at the Social Security wage base of $184,500 (Mass.gov).
Pre-tax deductions
Massachusetts taxes employee 401(k)/403(b) deferrals, so they do not reduce Massachusetts withholding here. Section 125 health premiums are treated as pre-tax.
Federal income tax, Social Security and Medicare
Federal withholding uses the IRS 2026 percentage method for automated payroll systems (Publication 15-T, Worksheet 1A). Social Security is 6.2% of wages up to the $184,500 wage base, and Medicare is 1.45% of all wages plus 0.9% Additional Medicare Tax on wages above $200,000. Per-paycheck Social Security and Medicare are shown as a yearly average: if you pass the wage base, your later paychecks will show none.
What this calculator does not include
This estimate does not cover bonuses or other supplemental wages, multiple jobs, Roth (after-tax) contributions, HSA payroll contributions, wage garnishments, or tips and overtime deductions unless you enter them on Form W-4 Step 4(b). Full-time student and other Circular M special cases are not modeled; your employer may pay part of the PFML contribution. See the methodology for details.
Frequently asked questions
Does Massachusetts withhold the 4% millionaire surtax?
Yes. Circular M (2026) applies 9% (5% + 4%) to annualized wages above $1,107,750.
How much is MA PFML in 2026?
Up to 0.46% of wages for employees (0.18% family + 0.28% medical), up to $184,500 of wages, so at most $848.70 for the year.
Why does my 401(k) not reduce my Massachusetts tax?
Massachusetts does not exclude elective deferrals to 401(k) plans from state wages, so they remain subject to state withholding.
How is federal income tax withholding calculated?
We follow Worksheet 1A of IRS Publication 15-T (2026) for a 2020-or-later Form W-4: your taxable pay is annualized, adjusted by the Form W-4 entries (Step 2 checkbox, Step 3 credits, Step 4 other income, deductions and extra withholding), run through the 2026 percentage-method table for your filing status, and divided back by your number of paychecks. Our engine reproduces all 4,350 cells of the IRS 2026 wage-bracket tables for weekly, biweekly, semimonthly and monthly pay.
Why does Social Security stop at $184,500?
For 2026 the Social Security (OASDI) wage base is $184,500 (SSA). The 6.2% employee tax applies only to wages up to that amount each year. Medicare (1.45%) has no cap, and employers must withhold an extra 0.9% Additional Medicare Tax on wages above $200,000 in the year, regardless of filing status.
Is withholding the same as the tax I will owe?
No. Withholding is an estimate taken from each paycheck. Your actual tax is settled when you file your return and depends on all your income, deductions and credits, so you may get a refund or owe more.
Official sources
- Massachusetts DOR: Circular M, Income Tax Withholding Tables (effective January 1, 2026)
- Mass.gov: Paid Family and Medical Leave contribution rates
- IRS Publication 15-T (2026), Federal Income Tax Withholding Methods
- IRS Rev. Proc. 2025-32 (2026 tax brackets and standard deduction)
- SSA: 2026 Social Security wage base ($184,500)
- IRS Topic 560: Additional Medicare Tax