What's an example of how the formula works?

For a family earning $2,000 per week, support is computed as $346 plus 18% of income above $1,600, illustrating how the formula scales with income above a base threshold rather than applying a single flat percentage.

What changed in the 2025 guidelines?

The maximum combined income used for calculations increased from $400,000 to $450,000, effective with the worksheet dated December 1, 2025.

How do I request a modification in Massachusetts?

File a motion to modify the existing support order with the Probate and Family Court, explaining to the judge why your ability to pay (or need for support) has changed. This requires going back to court rather than adjusting payments independently.

How is child support enforced in Massachusetts?

Wage garnishment is the most common method, with DOR's Child Support Services Division withholding income directly from a parent's paycheck. DOR uses an escalating set of administrative tools requiring no new court hearing: income withholding, then tax intercepts, bank levies, liens, and license suspension.

Massachusetts, United States

Massachusetts Child Support: A Parent's Guide

Q: How is child support calculated in Massachusetts?

Judges use the Child Support Guidelines Worksheet (CJD 304), based on a formula tied to each parent's gross weekly income, which includes salaries, wages, bonuses, overtime, commissions, pensions, annuities, and self-employment earnings.

How child support works in Massachusetts, in plain English: the 2025 guidelines worksheet, modification, and DOR enforcement.

Legal sources reviewed: August 10, 2026

On this page

In short: Massachusetts calculates support using a formula tied to gross weekly income, with a maximum combined income figure that rose to $450,000 under the December 2025 guidelines. Modifications require going back to the Probate and Family Court, and the Department of Revenue (DOR) enforces largely through automatic administrative tools, no new court hearing required at each step.

This is an educational overview written for parents, not lawyers. It isn't legal advice. For anything beyond general understanding, talk to a licensed Massachusetts family law attorney.

What Massachusetts generally provides

Massachusetts judges use the Child Support Guidelines Worksheet (CJD 304) to calculate support, based on a formula tied to each parent's gross weekly income, which includes salaries, wages, bonuses, overtime, commissions, pensions, annuities, and self-employment earnings.

Important terminology

CJD 304: the official Massachusetts Probate and Family Court Child Support Guidelines Worksheet.
Gross weekly income: the base figure for Massachusetts's formula, distinct from the monthly or annual figures other states use.
DOR / CSSD: the Department of Revenue's Child Support Services Division, which enforces most orders.

How the calculation works

A base amount plus a percentage above a threshold

Massachusetts's formula scales with income rather than applying a single flat percentage across the board. For example, a family earning $2,000/week owes $346 plus 18% of income above $1,600, illustrating the base-plus-marginal-percentage structure rather than one flat rate applied to the full income figure.

The 2025 update

The 2025 Massachusetts Child Support Guidelines, effective with the worksheet dated December 1, 2025, raised the maximum combined income used in calculations from $400,000 to $450,000, the ceiling above which the standard guideline formula no longer automatically applies.

Requesting or defending a modification

A parent who can't afford their current payments (or believes support should increase) must file a motion to modify the existing order with the Probate and Family Court, explaining the change in circumstances to the judge. This requires an affirmative court filing, not a unilateral payment change. See the child support calculator and guideline finder for jurisdiction-specific calculation sources and guidance.

How enforcement works

Wage garnishment is the most common enforcement method, with the Department of Revenue's Child Support Services Division (DOR/CSSD) withholding income directly from the paying parent's paycheck. DOR enforces back child support through an escalating set of administrative tools that require no new court hearing: beginning with income withholding and progressing to tax intercepts, bank levies, liens, and license suspension. Notably, if a modification happens outside of DOR's involvement, the parent must notify DOR directly and file the updated order, otherwise DOR continues enforcing based on the older order in its records.

Common questions

Do I need to tell DOR if my order gets modified in court? Yes. If DOR isn't formally notified with a copy of the new order, it will continue to assess and enforce support based on the prior court order in its system, even if a judge has since changed the amount.

Does the formula apply the same percentage no matter the income level? No, Massachusetts uses a base-plus-marginal-percentage structure that changes with weekly income, not a single flat rate across all levels.

What if my co-parent isn't paying? Contact DOR's Child Support Services Division (CSSD), which can escalate through withholding, tax intercepts, and license suspension without needing a new court hearing at each step.

Practical considerations

Because DOR's enforcement continues based on whatever order is in its records, always send DOR a copy of any court-ordered modification directly rather than assuming the court and DOR are automatically in sync, this is a real, recurring source of enforcement mismatches. For the custody arrangements underlying the parenting-time side of a Massachusetts support case, see the Massachusetts custody guide.

Official Massachusetts resources

FAQ

Questions, answered

This information is provided for educational purposes only and is not legal advice. Family law varies by individual circumstances and may change over time. Consult a qualified attorney or appropriate official resource for advice about your situation.