Child support in Massachusetts

Massachusetts uses the Income Shares model. This guide covers how it works, what documents to gather, and where the official calculator lives, verified for 2026.

How Massachusetts calculates support

The Income Shares combines BOTH parents' incomes, looks up the guideline support amount for that combined income and the number of children, then splits the obligation between the parents in proportion to their incomes. Parenting time, health insurance, and childcare costs adjust the result.

Massachusetts 2021 Guidelines include a specific parenting time adjustment (up to 10% reduction for parenting time exceeding 40%) that may differ from this estimate.

Before any court filing, confirm your number with Massachusetts's official calculator or worksheet.

Documents you will need

Run your estimate and keep the record

CoreParent's calculator covers all 50 states with Massachusetts's model, keeps your assumptions, and produces a record you can keep alongside your parenting plan and shared expenses. Support math lives best in the same system as your calendar and expense record.

Estimate free

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