Calculators5 min readUpdated: 2026-09-15
What Is the Income Shares Model in Child Support? Legal Definition
Definition
The Income Shares model is a child support calculation methodology that estimates child-rearing expenditures based on combined parental income, dividing the obligation proportionately.
Detailed Technical Breakdown
Adopted by more than 40 US states, the Income Shares Model was developed by the National Center for State Courts (NCSC) on the premise that a child should receive the same proportion of parental income that they would have received if the parents had remained married in an intact single household. Parental incomes are summed to establish a basic support schedule obligation, which is then assigned between the parents based on their percentage share of combined income.
Key Technical Specifications
- Used across 41+ US jurisdictions including IL, IN, CA, FL, GA, and NY.
- Accounts for combined parental income rather than obligor income alone.
- Incorporates mandatory statutory add-ons for health insurance and childcare.
- Applies parenting time overnight credits for active non-custodial parents.
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