What Is Income Shares Model
The income shares model is a child support calculation method used in 41 states that determines support based on what both parents would have spent on their child if the family remained intact. Rather than assigning all support to one parent, this model divides the obligation proportionally based on each parent's income percentage and custody time.
How the Calculation Works
The income shares model operates through a multi-step process. First, both parents' gross incomes are combined to establish a total household income. States then reference child support guidelines tables, which specify a base support amount for that combined income level. For example, many states set the base support for a combined income of $60,000 with one child at approximately $800 to $1,200 per month, depending on state law.
Next, each parent's income share is calculated. If Parent A earns $40,000 and Parent B earns $20,000 from a $60,000 combined income, Parent A holds a 66.7% share and Parent B holds a 33.3% share. The base support obligation is then divided according to these percentages. Custody time adjusts the calculation further. A parent with primary custody (more than 50% overnights) pays a reduced share because the custodial parent covers direct expenses during their time. States typically reduce support by 5% to 25% for each additional overnight above a threshold, usually around 109 overnights per year.
State-Specific Variations
Income shares implementation differs by state. Some states (Connecticut, Georgia, South Carolina) use strict income shares; others blend it with flat percentage models. Income caps also vary. Many states cap income at $150,000 to $250,000 annually, requiring judges to exercise discretion above that threshold. The definition of "income" varies too. Some states include bonus income and investment returns; others exclude them. Imputed Income rules differ significantly. States like California may impute income to a parent who voluntarily reduces hours, while others apply this only in cases of demonstrated underemployment.
Practical Implications for Your Divorce
- Custody arrangement directly affects the dollar amount. Shifting from 30% to 50% custody time can reduce your support obligation by 10% to 15%.
- Income documentation is critical. You will need to provide tax returns, pay stubs, and employment verification. Discrepancies trigger detailed income analysis.
- Self-employment income calculations are more complex and subject to expense deductions that salaried income avoids.
- Changes in custody or income after the divorce can justify modification. Most states allow review every three years or upon material change (20% income shift).
- The model assumes both parents contribute to child expenses, so neither parent receives a tax deduction for the full support amount paid.
Common Questions
- Does my state use income shares? Check your state's Department of Child Support Services website or consult a local family law attorney. Your state guidelines document specifies the exact formula and tables used.
- Can the income shares amount be negotiated? Yes. You and your ex can agree to any amount through a written settlement, as long as the court finds it reasonable. Courts can deviate from guideline amounts if both parties consent and the arrangement serves the child's best interests.
- What happens if a parent refuses to disclose income? The court can impute income based on employment history, earning capacity, or local wage data. Courts commonly impute income at minimum wage or the parent's historical earning average, whichever is higher.