CoreParent™

Massachusetts child support: weekly percentages, three parenting boxes, and a worked example

Massachusetts sets child support by the week. The 2025 Child Support Guidelines, in force since December 1, 2025, apply falling percentages to the parents' combined available income, multiply by a factor for the number of children, and let the worksheet handle shared, two-thirds and split parenting plans.

Estimate free

At a glance

ModelMarginal percentages of combined available gross income (Table A), shared by income; 2025 Guidelines, effective December 1, 2025
Pay periodWeekly: every figure on the worksheet and in the order is per week
Income cap$450,000 combined a year ($8,654 a week); above that, the court decides, and the capped amount is the minimum presumptive order
More childrenOne-child amount times 1.40 for two, 1.68 for three, 1.85 for four, 1.94 for five
Low incomePayor earning $301 a week or less: no more than $15 a week. $302 to $391: no more than $33
Support can run to21 if the child lives with and depends on a parent; 23 if also enrolled in an undergraduate program (court's discretion after 18)
AgencyChild Support Services, Massachusetts Department of Revenue (DOR)

How Massachusetts calculates child support

The guidelines start from gross income from whatever source, a list of 30 categories that runs from wages, bonuses and self-employment profit to rental income, stock options and alimony received. Means-tested benefits such as SNAP, TAFDC and SSI are not counted. Each parent may then deduct health and dental/vision premiums they actually pay and support they actually pay for other children. What is left is that parent's available income, Line 3a of the worksheet.

The two available incomes are added and run through Table A, which works like tax brackets: 22% of the first $1,000 a week, 21% of the next $600, 18% up to $2,400, 14% up to $3,500, 11% up to $5,000 and 10% up to $8,654. That gives the amount for one child. Table B scales it for more children, and each parent's percentage of the combined income decides how the total is split.

A completed Guidelines Worksheet (CJD 304) is required in every case where support is set or changed, whatever the income. If the parties agree to an amount that differs from the worksheet, the court must make written findings on the Findings and Determinations form (CJD 305) and approve the deviation.

Worked example: Massachusetts

  1. Parent A has $1,650 a week of available income and Parent B has $1,100, so combined available income is $2,750 a week.
  2. Table A at $2,750 is $490 plus 14% of the amount over $2,400, or $539 for one child. For two children Table B multiplies by 1.40, so the combined weekly support amount is $755.
  3. Parent A earns 60% of the combined income, so Parent A's share is $453 and Parent B's share is $302.
  4. If the children live with Parent B about two-thirds of the time (box 2 on the worksheet), Parent A pays $453 a week, before any child care adjustment. That is well under the 40% of income that triggers the hardship presumption.

This is an estimate, not legal advice. Figures are rounded to the dollar and leave out the insurance, childcare, and other adjustments your case may have. Try your own numbers in CoreParent's calculator, then confirm with the state's official calculator.

Parenting time in Massachusetts: shared, two-thirds, or split

The basic formula assumes the children live primarily with one parent and spend about one-third of the time with the other. Line 1b of the worksheet offers three boxes: shared (financial responsibility and parenting time approximately equal), primary residence with one parent for about two-thirds of the time, and split (each parent is the primary home for at least one child).

With the shared box, the worksheet figures what each parent would owe the other and the higher earner pays the difference. In the example, equal time leaves Parent A paying about $151 a week. There is no sliding formula between one-third and one-half: a parent with substantially more than one-third but less than half the time can ask the court to deviate, and a parent with substantially less than one-third may face an upward deviation. The Appeals Court has also upheld a judge who ran both boxes and ordered an amount in between.

Child care, health insurance and medical bills

Out-of-pocket child care needed for a parent to work, after discounts and subsidies, is shared in proportion to income up to $430 per child per week, a benchmark based on the average cost of infant care in Massachusetts. Health premiums are handled differently: each parent deducts what they pay from income instead of splitting the bill. Coverage counts as reasonable in cost if it is no more than 5% of the gross income of the parent who provides it, and as accessible if services are within 15 miles of the child's primary home.

The recipient pays the first $250 a year of routine uninsured medical, dental and vision costs for all the children combined. Above that, the court allocates the costs without changing the weekly order, and the 2025 commentary encourages splitting them by income share rather than defaulting to half each. Orthodontia, counseling and other extraordinary costs are decided case by case.

Low incomes, high incomes and the 40% check

For 2025 the two lowest brackets were tied to the federal poverty guideline for one person: a payor with gross income of $301 a week or less should owe no more than $15 a week, and one earning $302 to $391 no more than $33. The court can still deviate, down to $0, when circumstances warrant. At the other end, an order that takes 40% or more of the payor's available income is presumed to be a substantial hardship that justifies a deviation.

The guidelines stop at $450,000 of combined income a year. Above it, the amount at $450,000 is the minimum presumptive order and anything more is discretionary, but any percentage the court applies to the excess should be lower than the 10% top bracket in Table A.

Other children and alimony

Support a parent actually pays under an earlier order comes off gross income, though payments on arrears do not. Reasonable voluntary payments for a child living elsewhere can also be deducted. For a child who lives with the parent and has no order, the worksheet computes a hypothetical support amount using both of that child's parents' incomes and deducts it.

When alimony is also on the table, the Supreme Judicial Court's decision in Cavanagh v. Cavanagh (2022) requires the judge to run it both ways, alimony first and child support first, compare the results and their tax effects, and choose the most equitable order for the family.

Support after 18 and college costs

Massachusetts law lets a court order support for a child aged 18 to 21 who lives in a parent's home and is principally dependent on that parent, and up to 23 if the child is also enrolled in an educational program, excluding costs beyond an undergraduate degree. It is discretionary, not automatic. A child of 18 or older still in high school is treated as under 18; otherwise the worksheet reduces the amount with Table C, by 25% when every child covered is 18 or older.

Contribution to college is separate and also discretionary. Absent written findings that a parent can afford more, no parent pays more than half of the in-state undergraduate cost (fees, tuition, housing, meal plan and books) at the University of Massachusetts Amherst, wherever the child actually enrolls.

Changing an order

Under M.G.L. c. 208, s. 28, an order shall be modified when there is an inconsistency between it and the amount the current guidelines produce, or when the child's health coverage needs to be addressed. The guidelines add lost or newly available coverage and any other material and substantial change. If the old order was a deviation, the deviation carries over only while the facts behind it still exist and it remains in the child's best interests.

Collection and enforcement

Child Support Services at the Department of Revenue establishes parentage and gets, changes and enforces orders, and on either parent's request reviews whether to ask the court for a modification. Unpaid support becomes a lien on the payor's property as of the date it was due, and the agency can withhold wages, intercept tax refunds, seize bank accounts, report to credit bureaus and deny passports.

Documents you will need

Massachusetts child support FAQ

What is the Massachusetts child support calculator for 2026?

The official tool is the Probate and Family Court's fillable 2025 Child Support Guidelines Worksheet (CJD 304), which applies the guidelines in effect since December 1, 2025. Those 2025 guidelines are still the current version in 2026.

How is child support calculated in Massachusetts?

Subtract health premiums and prior support from each parent's gross weekly income, add the two, apply the Table A percentages, multiply by the Table B factor for the number of children, and divide by income share. The parenting-time box and child care then adjust the result.

How much is child support for 2 kids in Massachusetts?

At $2,750 a week of combined available income, the two-child amount is $755 a week. A parent with 60% of that income and about one-third of the time would pay $453 a week before child care.

Does 50/50 custody mean no child support in Massachusetts?

Not unless incomes are about equal. With the shared box checked, the higher earner pays the difference between the two parents' shares. With a 60/40 income split and two children at $2,750 a week, that is about $151 a week.

Does child support end at 18 in Massachusetts?

Not necessarily. A court may continue support to 21 for a child who lives with and depends on a parent, and to 23 for one enrolled in an undergraduate program. It may also order a separate contribution to college costs.

Next steps

Sources

Verified against these official sources in October 2026:

Child support in every other state

All states

This is general educational information, not legal advice, and official figures change. Last verified: October 2026. Consult a licensed family-law attorney in Massachusetts.