Shared, Split and Primary Care in Massachusetts Child Support
The Massachusetts worksheet has three parenting boxes: shared (about equal time and costs), children mainly with one parent (about two-thirds of the time) and split (each parent has at least one child), and the court may deviate when the actual parenting time does not fit them.
Three boxes on line 1b
The worksheet asks whether the parents (1) share financial responsibility and parenting time approximately equally, (2) have the children living primarily with one parent for about two-thirds of the time, or (3) are in a split arrangement in a family with more than one child where each parent provides a primary residence for at least one child (Guidelines section II.D). The calculation is built on the assumption that the children live mainly with one parent and spend about one-third of the time with the other.
Shared (box 1)
Each parent is treated as having all of the children. The worksheet runs the support calculation from each parent’s side, adds each parent’s share of the other’s child care, adjusts for the other parent’s share of income when the amount is under 10% of the recipient’s income, and the parent who owes more pays the difference.
Split (box 3)
Each parent has the children who live with him or her. The calculation runs for the children with each parent, and the parent who owes the greater amount pays the difference.
When parenting time is not a fit
If the payor has substantially less than one-third of the parenting time, the court may deviate upward; if the non-residential parent has substantially more than one-third but less than half, the court may deviate with an adjustment (Sections II.D.3 and II.D.4 and IV.B.8 and 9). Where children have more than two legal parents, the court weighs the finances and parenting time of all of them.
An example
Two children, a father earning $2,000 a week and a mother earning $1,000, with $200 a week of child care paid by the mother and $40 a week of insurance paid by the father:
| Arrangement | Weekly order |
|---|---|
| Children live mainly with one parent (box 2) | $657 |
| Shared parenting, same incomes (box 1) | $387 |
| Shared parenting, incomes $1,500 and $2,500 with child care (box 1) | $357 |
The last line uses the same family with incomes of $1,500 and $2,500 and shared parenting.
Questions to bring to an attorney
Ask which box fits your parenting plan, and whether a deviation is likely if your time with the children does not fit the boxes.
Evidence that helps
A calendar of the actual parenting time, the parenting plan, and records of who pays for child care, insurance and the children’s other costs.
Frequently asked questions
What are the three boxes on the Massachusetts worksheet?
Box 1 is shared parenting, box 2 is the children living mainly with one parent about two-thirds of the time, and box 3 is a split arrangement.
What is a split arrangement in Massachusetts?
A family with more than one child covered by the order in which each parent provides a primary residence for at least one child.
Can parenting time change Massachusetts child support?
The boxes set the worksheet, and the court may deviate when parenting time is substantially less than one-third or between one-third and one-half.
Is there an overnight count for Massachusetts child support?
No. The worksheet uses the three boxes of approximately equal, about two-thirds, or split, not a count of overnights.
Does Massachusetts allow more than two legal parents?
Yes. The guidelines tell the court to consider the finances and parenting time of all legal parents and allow a deviation.
Official sources
- 2025 Massachusetts Child Support Guidelines (effective December 1, 2025)
- Child Support Guidelines Worksheet (CJD 304), 2025
- Massachusetts Trial Court: Child Support Guidelines
A local family law attorney can review your situation — many offer a free consultation.
This is general information, not legal advice. It is based on the cited Massachusetts statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed Massachusetts attorney.