Massachusetts Child Support Guidelines

Massachusetts calculates child support using a detailed set of Child Support Guidelines that are reviewed and updated regularly by a task force appointed by the Chief Justice of the Trial Court. These guidelines apply to all child support determinations in the state, whether the parents are married, divorced, or were never married. The guidelines create a presumptive child support amount based on both parents’ incomes, the number of children, and several adjustment factors.

Understanding how the guidelines work — and when a court might deviate from them — is essential for any parent involved in a child support case in Massachusetts.

For a general overview of how child support works across the country, see our guide on how child support is calculated.

The Income Shares Model

Massachusetts uses the income shares model for calculating child support. This model is based on the principle that children should receive the same share of parental income they would have received if the family remained intact. Rather than looking at just one parent’s income, the model considers both parents’ combined income to determine the total support obligation, then assigns each parent a proportional share based on their individual contribution to the total.

The income shares model is used by the majority of states and is widely considered the most accurate way to estimate the cost of raising a child at a particular income level.

How the calculation works at a high level

1. Determine each parent’s gross income
2. Combine both parents’ gross incomes
3. Look up the presumptive child support amount on the guidelines worksheet based on combined income and the number of children
4. Calculate each parent’s percentage share of the combined income
5. Assign each parent a proportional share of the support obligation
6. Apply adjustments for health insurance, childcare, and parenting time
7. The parent without primary custody (or with less parenting time) typically pays the resulting amount to the other parent

Gross Income Definition

The Massachusetts Child Support Guidelines define gross income broadly. This is the starting point for the entire calculation.

Gross income includes:

• Salaries, wages, overtime, tips, and commissions
• Self-employment income (gross receipts minus ordinary and necessary business expenses)
• Severance pay
• Pensions, annuities, and Social Security benefits
• Unemployment compensation and workers’ compensation
• Disability insurance benefits
• Veterans’ benefits
• Military pay and allowances
• Investment income, including interest, dividends, and capital gains
• Trust income and annuities
• Rental income
• Income from royalties, patents, and copyrights
• Alimony or separate maintenance received from the current or any prior relationship
• Income from most other sources

Items excluded from gross income:

• Means-tested public assistance benefits (TAFDC, SNAP, SSI)
• Income earned by a new spouse or domestic partner (though it may be relevant in deviation analysis)
• Child support received for children of a different relationship

Imputed income

If a parent is voluntarily unemployed or underemployed, the court may impute income to that parent. This means the court assigns income based on what the parent could earn given their education, training, work experience, and job availability in the local market. The purpose is to prevent a parent from artificially reducing their income to lower their child support obligation.

The court considers whether the parent’s decision to reduce income was made in good faith — for example, returning to school or caring for a young child — or was motivated by a desire to avoid support obligations.

The Child Support Guidelines Worksheet

The guidelines include a worksheet that parents and attorneys use to calculate the presumptive support amount. The worksheet follows a step-by-step process:

1. Enter each parent’s weekly gross income. Massachusetts calculates child support on a weekly basis.
2. Subtract certain costs from each parent’s gross income, including:
   • The cost of health insurance for the child (the portion attributable to the child only)
   • The cost of dental and vision insurance for the child
   • Childcare costs necessary for the parent to work or attend school
   • Child support paid for children from other relationships
3. Combine the adjusted incomes of both parents.
4. Look up the combined income on the guidelines table to find the base child support amount for the applicable number of children.
5. Divide the support obligation proportionally based on each parent’s share of the combined income.
6. Apply a parenting time adjustment if the payor has the child for a significant amount of time.

Income cap

The guidelines provide presumptive amounts for combined gross incomes up to $450,000 per year (updated December 2025). For incomes above this cap, the court has discretion to set the support amount, considering the child’s needs and the standard of living the child would have enjoyed if the family remained together.

Presumptive Amounts and the Guidelines Table

The guidelines table sets forth the presumptive child support obligation based on combined gross income and the number of children. The presumptive amount represents the percentage of combined income that the guidelines estimate would be spent on the child in an intact household.

As combined income increases, the percentage spent on children generally decreases, even though the dollar amount increases. For example, parents with lower combined incomes may be expected to spend a higher percentage of their income on children than parents with higher combined incomes.

The court treats the guidelines amount as presumptively correct. This means the court must order the guidelines amount unless there is a specific reason — supported by written findings — to deviate.

Deviation Factors

Courts may deviate from the presumptive guidelines amount when applying it would be unjust or inappropriate in a particular case. The guidelines list specific factors the court may consider:

• Extraordinary medical or dental expenses not covered by insurance
• Extraordinary educational expenses for the child (such as private school tuition, tutoring, or special needs services)
• The financial resources of the child — for example, a child who has a trust fund or other independent income
• The standard of living the child would have enjoyed if the family remained intact
• The parent’s ability to provide health insurance or cash medical support
• Income of a new spouse or partner — while not included in the base calculation, the court can consider it if excluding it would produce an unjust result
• Extraordinary travel expenses for parenting time
• A parent’s existing child support obligations for other children
• The tax consequences of the support arrangement
• Agreements by the parties — if both parents agree to deviate, the court may approve the deviation so long as the child’s needs are met

If the court deviates from the guidelines amount, it must provide written findings explaining the reason for the deviation and how the adjusted amount meets the child’s needs.

Healthcare Costs

Healthcare coverage is a critical component of child support in Massachusetts. The guidelines address healthcare in several ways:

Health insurance premiums

The cost of providing health insurance for the child is factored into the support calculation. If one parent provides insurance through their employer, the cost attributable to the child (not the parent’s own coverage) is subtracted from that parent’s gross income before calculating the support obligation. This effectively shares the insurance cost proportionally between the parents.

Uninsured medical expenses

The guidelines presume that uninsured medical, dental, and vision expenses for the child will be split proportionally between the parents based on their income shares. This includes co-pays, deductibles, and costs for services not covered by insurance.

The court may order a different allocation if circumstances warrant.

Childcare Costs

Work-related childcare costs — daycare, after-school programs, summer camps, and similar expenses that allow a parent to work or attend school — are addressed in the guidelines. Like health insurance, childcare costs are subtracted from the paying parent’s gross income before the support calculation. This shares the cost between both parents proportionally.

Childcare expenses must be reasonable and necessary. The court may scrutinize unusually high childcare costs or costs that do not appear related to a parent’s employment or education.

Parenting Time Adjustment

The Massachusetts guidelines include an adjustment for cases where the payor parent has significant parenting time. The adjustment recognizes that a parent who has the child for a substantial amount of time incurs direct costs — food, utilities, activities — that reduce the need for a full support payment to the other parent.

The guidelines apply different adjustment factors based on the parenting time arrangement:

• If the payor has the child approximately one-third of the time (roughly two overnights per week), a modest reduction applies.
• If the parents share parenting time equally or close to equally, the adjustment is more significant, though it does not eliminate the support obligation when there is an income disparity.

The exact adjustment is built into the guidelines worksheet and depends on the specific schedule and income ratio.

For more on how equal custody affects child support, see our guide on child support with 50/50 custody.

College Costs: Support for Children Ages 18-23

Massachusetts is one of a limited number of states where the court can order child support for adult children who are pursuing higher education. Under MGL Chapter 208, Section 28, the court has the authority to order support for children between the ages of 18 and 23 who are domiciled in the home of a parent and are principally dependent on that parent for maintenance.

This provision most commonly applies when a child is enrolled in an undergraduate educational program. The court can order a parent to contribute to the child’s college tuition, room and board, and related educational expenses as part of the support obligation.

Key considerations for college support

• The child must be domiciled in the home of a parent and principally dependent on that parent
• The child must be enrolled in an educational program (typically college or vocational training)
• The court considers each parent’s financial ability to contribute and the child’s own resources (such as scholarships, financial aid, and part-time employment income)
• The court is not required to order support through age 23 — it is discretionary
• Parents who want to address college costs in advance can include provisions in their separation agreement

How to Modify a Child Support Order

Child support orders in Massachusetts can be modified when there has been a material and substantial change in circumstances since the original order. Common grounds for modification include:

• A significant increase or decrease in either parent’s income
• Loss of employment or involuntary reduction in hours
• A change in the child’s needs (such as new medical or educational expenses)
• A change in the parenting time arrangement
• The guidelines themselves being updated (which can create an automatic basis for modification if the existing order differs significantly from the updated guidelines amount)

The modification process

To modify child support, the requesting parent must file a Complaint for Modification with the Probate and Family Court. The parent must demonstrate that the change in circumstances is not temporary and that it warrants a different support amount.

The court recalculates support using the current guidelines and current financial information. If the new guidelines amount differs substantially from the existing order, the court typically modifies the order.

Retroactivity

Modifications generally take effect from the date the complaint for modification is filed, not from the date the change in circumstances occurred. This means it is important to file promptly when circumstances change. Back support obligations that accrued before the filing date are typically not reduced retroactively.

Enforcement

If a parent falls behind on child support payments, Massachusetts has robust enforcement tools available through the Department of Revenue, Child Support Enforcement Division (DOR/CSE). Enforcement actions include:

• Income withholding (wage garnishment)
• Interception of tax refunds (state and federal)
• Suspension of driver’s licenses and professional licenses
• Credit bureau reporting
• Liens on real and personal property
• Contempt of court, which can result in fines or incarceration

For more on enforcement options, see our guide on child support enforcement.

What to Do Next

1. Gather your financial documents. The child support calculation requires accurate income information from both parents. Collect recent tax returns, pay stubs, W-2s, 1099s, and documentation of any other income sources.
2. Review the current guidelines. The Massachusetts Child Support Guidelines are updated periodically. Make sure you are using the most current version when estimating your support obligation.
3. Understand your parenting time arrangement. The amount of time each parent spends with the child directly affects the support calculation. Have a clear picture of the actual parenting schedule.
4. Plan for healthcare and childcare costs. These costs are factored into the calculation separately from basic support. Know what you are paying and what the child needs.
5. Talk to a family law attorney. Child support calculations can be complicated, especially when income is variable, a parent is self-employed, or college costs are on the horizon. Schedule a free consultation to get guidance specific to your situation.

Frequently Asked Questions

How often are the Massachusetts Child Support Guidelines updated?

The guidelines are reviewed and updated periodically by a task force appointed by the Chief Justice of the Trial Court. Updates typically occur every four years, though the exact schedule can vary. When the guidelines are updated, existing orders may be eligible for modification if the new guidelines produce a significantly different amount.

Can Massachusetts courts order parents to pay for college?

Yes. Under MGL Chapter 208, Section 28, the court can order support for children between the ages of 18 and 23 who are domiciled with a parent and principally dependent on that parent. This can include contributions toward college tuition, room and board, and related educational expenses. The court considers each parent’s financial ability and the child’s own resources.

What happens if a parent is not working?

If a parent is voluntarily unemployed or underemployed, the court may impute income to that parent based on their earning capacity. The court looks at the parent’s education, work history, skills, and the local job market. If the parent reduced their income in good faith — for example, to care for a young child — the court may not impute income or may impute a lower amount.

How is child support affected by equal parenting time?

When parents share parenting time equally or close to equally, the guidelines apply a parenting time adjustment that reduces the support obligation. However, child support is not eliminated even in a 50/50 arrangement if there is a significant income difference between the parents. The higher-earning parent still pays support, though the amount is reduced to account for the direct costs they incur during their parenting time.

Can I modify my child support order if I lose my job?

Yes, but you must act promptly. An involuntary loss of employment is generally considered a material and substantial change in circumstances that can justify modification. File a Complaint for Modification with the court as soon as possible, because the modification typically takes effect from the filing date — not from the date you lost your job. Do not simply stop paying, as arrears will continue to accrue under the existing order until it is formally modified.