Massachusetts Child Support Calculator

Estimate Massachusetts child support for 2026 using the Income Shares (Massachusetts variant) guideline model under Massachusetts Child Support Guidelines (G.L. c. 208 § 28). Enter both parents' incomes and the parenting-time split to see what you may owe or receive.

Massachusetts follows the Income Shares model under the Massachusetts Child Support Guidelines. The court combines both parents' monthly net incomes, looks up the basic support obligation on the state's guideline schedule for that income level and number of children, then prorates the obligation between the parents according to each parent's percentage share of the combined income.

Massachusetts uses a shared-care formula rather than a simple per-overnight credit. When parents roughly share physical custody, the Massachusetts Child Support Guidelines run a separate shared physical custody calculation that can lower the support number compared to a standard order. The more balanced the parenting time, the more the formula reflects each parent's direct spending on the child. The on-page calculator here is only an estimate, so confirm any shared-custody result against the official worksheet.

The cost of providing the child's health, dental, and vision insurance is treated as an adjustment in the Massachusetts guideline calculation. The premium attributable to the child is factored in so the parent who pays it gets credit, which shifts the final support figure. This keeps the parent who actually carries the coverage from absorbing the full cost alone. Enter the real premium amounts on the official Massachusetts worksheet to see the controlling result.

Work-related child care costs are listed as a guideline adjustment in Massachusetts, alongside health insurance and prior support orders. Day care and similar care expenses tied to a parent's employment are factored into the calculation rather than ignored. Because these costs change the bottom-line obligation, document them accurately. The on-page estimate cannot capture every family's care arrangement, so the official Massachusetts Child Support Guidelines worksheet is what controls the actual number.

A Massachusetts judge in Probate and Family Court can deviate from the guideline amount when applying it strictly would be unjust or not in the child's best interest, given the specific facts of the case. The parent asking for a different number bears the burden of showing why the guideline figure should not apply, and the court must make written findings explaining any deviation. Deviation is the exception, not the norm, so most orders track the Massachusetts Child Support Guidelines closely.

Frequently asked questions

How is child support calculated in Massachusetts?

Massachusetts follows the Income Shares model under the Massachusetts Child Support Guidelines (G.L. c. 208 section 28). The Probate and Family Court combines both parents' monthly net incomes, looks up the basic support obligation on the state's guideline schedule for that income level and number of children, then prorates it between the parents by each parent's percentage share of the combined income. Adjustments for health, dental, and vision insurance, child care, and prior support orders are then applied. The calculator on this page is an estimate only. The official worksheet and a licensed attorney control your actual order.

Is there an official Massachusetts child support worksheet I have to use?

Yes. The Massachusetts Child Support Guidelines worksheet and form, published by the state at mass.gov, is the controlling document. The Probate and Family Court uses that worksheet to combine incomes, apply the guideline schedule, and add credits for insurance and child care, and judges expect it to be completed for support orders and modifications. Any number you get from the estimator on this page is just a preview. Always complete the official Massachusetts worksheet, and consider having a licensed Massachusetts attorney review it, because that form and the court, not an online estimate, decide the final amount.

What income counts when Massachusetts sets child support?

The Massachusetts guidelines define income broadly. It includes salary, wages, commissions, self-employment earnings, bonuses, severance, royalties, rental income, retirement, Social Security, workers' compensation, unemployment, and interest. Income from almost any source is on the table, while means-tested public benefits are excluded. After income is identified, Massachusetts works from each parent's net income to build the guideline calculation. Because self-employment and bonus income can be complex, the Massachusetts Department of Revenue, Child Support Enforcement Division and the court may look closely at documentation. The estimate here is not legal advice, so verify your figures on the official worksheet.

How does sharing custody 50/50 change support in Massachusetts?

Massachusetts uses a shared-care formula rather than a flat overnight credit. When parents share physical custody, the Massachusetts Child Support Guidelines run a separate shared physical custody calculation that can produce a lower obligation than a standard order, because both households are directly supporting the child more equally. There is also a distinct calculation for split custody when each parent has primary care of different children. The result still depends on each parent's net income share. Run your specific numbers through the official Massachusetts worksheet, since the calculator here is only an estimate.

What can I do if a Massachusetts parent is unemployed or hiding income?

Massachusetts courts can address an unemployed or underemployed parent and scrutinize income that does not match a parent's earning history or lifestyle. Because the guidelines count income from nearly every source and exclude only means-tested benefits, a parent cannot simply walk away from earning capacity to dodge support. If you suspect hidden self-employment, cash, or bonus income, gather documentation and raise it in Probate and Family Court or through the Department of Revenue, Child Support Enforcement Division. These are fact-specific arguments, so a licensed Massachusetts attorney can help. The on-page calculator is only an estimate.

When does child support end in Massachusetts?

Standard termination of child support in Massachusetts is age 18. However, support can continue up to age 23 if the child is principally dependent on the parent and is pursuing a full-time post-secondary education program. This means a Massachusetts order does not always stop the moment a child turns 18, especially when the young adult is in college and still financially dependent. Because eligibility for the extension is fact-specific, confirm the rule against the Massachusetts Child Support Guidelines and the actual language of your order. This page is an estimate and not legal advice.

How do I change or enforce a Massachusetts child support order?

To change an order, file a complaint for modification in Probate and Family Court or request a review through the Department of Revenue, Child Support Enforcement Division. Massachusetts does not require a fixed percentage change. An inconsistency between your current order and a fresh guideline calculation supports modification. For enforcement, DOR/CSE uses immediate income withholding, tax intercept, license suspension, lien filings, credit reporting, passport denial, and contempt referrals back to the Probate and Family Court. The estimate on this page is informational only, so rely on the official worksheet and a licensed Massachusetts attorney for your actual case.