How Child Support Is Calculated in Massachusetts: A Guide for Parents with Primary Custody

Child support can be one of the most emotionally and financially significant issues when parents separate or divorce. In Massachusetts, the state provides a set of guidelines that courts use to determine how much child support should be paid. These guidelines are designed to make sure that children maintain a standard of living that reflects the combined income of both parents — not just the one they live with most of the time.

So how is child support calculated, especially when one parent has primary custody? Let’s walk through how it works in Massachusetts.

Understanding Primary Custody

When one parent has “primary physical custody,” it means the child lives with that parent more than 50% of the time. This parent is often referred to as the “custodial parent,” and the other is the “non-custodial parent.”

Since the custodial parent typically bears more day-to-day expenses (housing, food, school-related costs, etc.), both parents are financially responsible for the child. This is where child support comes in — it helps balance the scales so that both parents contribute to the child’s well-being.

The Massachusetts Child Support Guidelines

1. Calculate Each Parent’s Gross Weekly Income

Gross income includes wages, salary, bonuses, overtime, commissions, pensions, rental income, and more. It does not deduct taxes or other withholdings.

2. Adjust for Certain Deductions

Some allowable deductions may include:

- Child support paid for children from a prior relationship

- Health insurance premiums

These amounts are subtracted from the gross income to get the “adjusted gross income.”

3. Apply the Guidelines

The state has a Child Support Guidelines Worksheet and accompanying chart that determines the appropriate child support amount based on:

- Number of children

- Combined weekly income

- Parenting time (primary or shared custody)

In most cases where one parent has primary custody, the non-custodial parent pays child support based on their income.

What Other Factors Might Affect the Amount?

- Health insurance costs: If one parent pays for health insurance for the child, that may be factored into the calculation.

- Child care costs: Work-related childcare expenses (like daycare) are also included.

- Parenting time: If the non-custodial parent has the child for more than one-third of the time (but not quite 50/50), the court might lower the payment slightly.

Can the Amount Be Changed Later?

Yes. Either parent can request a modification of the child support order if there's a substantial change in circumstances, such as:

- A change in income

- A change in parenting time

- Health issues

- A change in the child’s needs

Bottom Line

In Massachusetts, child support is designed to ensure that children receive adequate financial support from both parents, regardless of which parent has primary custody. The state follows specific guidelines that are based on income, time spent with the child, and other relevant expenses. When one parent has primary custody, the other typically pays support — but the amount is calculated carefully to reflect each parent’s financial contribution to the child’s life.

If you're navigating child support issues, it's always a good idea to consult a family law attorney or a mediator familiar with Massachusetts law to make sure your rights — and your child's needs — are fully protected.

Disclaimer: This post is for informational purposes only and is not a substitute for legal advice. For advice about your individual case, consult a licensed family law attorney.