What Is the MA Employee’s Withholding Exemption Certificate?

Massachusetts Form M-4 is the state withholding exemption certificate you give your employer so the right amount of state income tax comes out of each paycheck. Massachusetts taxes wages at a flat 5%, and the number of exemptions you claim on the M-4 controls how much of your pay is shielded from that withholding every pay period. Skip the form and your employer withholds at zero exemptions, which pulls more tax from each check than most workers actually owe.¹

What the Form Actually Controls

The M-4 does one job: it translates your personal situation into a number your employer’s payroll system can use. Each exemption you claim reduces the portion of your wages subject to the 5% withholding. More exemptions, less tax per check. Claim too many and you’ll owe money (plus possible penalties) at filing time. Claim too few and you’ve given the state an interest-free loan all year.

Your employer keeps the completed M-4 on file and uses it with the withholding tables in the Massachusetts Circular M to calculate the exact dollar amount deducted from each paycheck.²

How to Fill Out Each Line

The form walks you through a short set of lines that add up to your total exemption number. Read each one carefully; the rules shift based on age, marital status, and the age of your dependents.

Line 1 (personal exemption): enter “1.” If you are 65 or older, or will turn 65 before the end of the next calendar year, enter “2” instead.
Line 2 (spouse): if you’re married and your spouse qualifies for an exemption, enter “4.” If your spouse is 65 or older, or will be before next year, enter “5.”
Line 3 (dependents): enter the number of dependents who qualify under federal tax law. If any of your dependents will be under age 12 at the end of the year, add one extra to the total on this line. That bonus exemption applies once, no matter how many children are under 12.
Line 4 (total): add lines 1 through 3. This is the number your employer uses.
Line 5 (additional withholding): if you expect standard withholding to fall short, you can request an extra flat dollar amount be withheld from each paycheck.¹

The form also has a checkbox for head of household filers. If you qualify for that filing status, mark it. It changes how your employer applies the withholding tables to your wages.

When to Submit a New M-4

You can file a new M-4 any time your exemptions go up, such as after a marriage or the birth of a child. When your exemptions go down, the timeline tightens: you have 10 days to file an updated certificate. The form gives this example: if your dependent child earns enough income during the year that you’ll no longer provide more than half their support, you must submit a new M-4 within 10 days of realizing that change.¹

Other events that commonly reduce exemptions include divorce or legal separation, a dependent aging out of eligibility, and the death of a spouse. Failing to update when your exemptions decrease doesn’t just create a tax bill in April. It can also expose you to penalties for claiming exemptions you were no longer entitled to.

How the M-4 Differs From the Federal W-4

New employees fill out both the M-4 and the federal Form W-4 when they start a job. The two forms look similar and work differently, and that trips people up constantly.

The key point: Massachusetts does not allow you to claim the federal withholding deductions and adjustments that appear on the W-4. The M-4 instructions state this directly.¹ The federal form was redesigned in 2020 to replace allowances with estimated deductions and credits. Massachusetts kept its exemption-based system. The number you enter on your W-4 and the number on your M-4 will almost certainly differ, and that’s fine. They’re calculated under entirely separate rules.

The Tax Cuts and Jobs Act changes that reshaped the federal W-4 did not touch Massachusetts withholding law. Employers maintain both forms separately and run each through its own calculation.²

When Exemptions Alone Won’t Cover You

The M-4 only governs wage withholding. If you have significant income from other sources, like self-employment, rental property, investments, or gig work, paycheck withholding may not be enough. Massachusetts requires you to pay at least 80% of your annual income tax liability before filing, and if you expect to owe more than $400 in state tax on non-withheld income, you’re required to make quarterly estimated payments.³

Estimated payments are due April 15, June 15, and September 15 of the tax year, plus January 15 of the following year. The alternative, if your outside income is predictable, is to use M-4 Line 5 to pull extra withholding from each paycheck and close the gap that way.

The 4% Surtax on High Incomes

Since 2023, Massachusetts has imposed an additional 4% tax on taxable income above an inflation-adjusted threshold. For 2026, that threshold is $1,107,750. Income above it is taxed at 9% rather than 5%. If your household income approaches that range, standard M-4 exemptions won’t cover the extra liability, and you should either raise your Line 5 withholding or make estimated payments.⁴

Penalties for Overclaiming

Claiming more exemptions than you’re entitled to can trigger both civil and criminal consequences, and the form itself warns about this.¹ Under Massachusetts General Laws Chapter 62C, Section 73, willfully delivering a false document to the Department of Revenue is punishable by a fine of up to $10,000 ($50,000 for a corporation) and up to one year of imprisonment. More serious fraud, such as willfully filing a false return or aiding in the preparation of a fraudulent document, can bring felony charges carrying fines up to $100,000 ($500,000 for a corporation) and up to three years in prison.⁵

The practical lesson is simpler than the statute. Fill out the M-4 to match the exemptions you actually qualify for, update it within 10 days when something changes against you, and use Line 5 rather than inflated exemptions if what you really want is a different withholding amount.

1
Massachusetts Department of Revenue. Form M-4 Massachusetts Employee’s Withholding Exemption Certificate
2
Mass.gov. Withholding Taxes on Wages
3
Mass.gov. AP 241: Estimated Income Tax Payments
4
Massachusetts Department of Revenue. Massachusetts Circular M Income Tax Withholding Tables at 5.0% Effective January 1, 2026
5
General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 62C, Section 73