Child Support by State: Which Model Does Your State Use?
Child support is not calculated the same way in every state. While the federal government requires states to establish child support guidelines under Title IV-D of the Social Security Act, it gives states significant flexibility in choosing their calculation method. The result: two fundamentally different approaches that can produce dramatically different results for the same family.
This guide explains both models, shows you which states use which approach, and helps you understand how the formula applies to your specific situation.
The Two Models: A Quick Comparison
| Feature | Income Shares Model | Percentage of Income Model | |---|---|---| | Based on | Both parents' incomes combined | Paying parent's income only | | Receiving parent's income | Counts (reduces obligation) | Doesn't count | | Number of states | ~40 states | ~14 states | | Conceptual basis | Child gets same % as intact family | Simple, predictable formula | | Fairer when... | Incomes are similar | Significant income gap exists |
States by Calculation Model
States Using the Income Shares Model (~40 States)
The income shares model is the most widely adopted approach. These states consider both parents' incomes when determining the total child support obligation.
Key income shares states:
- California
- Florida
- New York
- Ohio
- Michigan
- New Jersey
- Virginia
- North Carolina
- Indiana
- Arizona
- Colorado
- Maryland
- Missouri
- Washington
- Oregon
- South Carolina
- Utah
- Connecticut
- Kansas
- Kentucky
- Louisiana
- Maine
- Montana
- Nebraska
- New Mexico
- Oklahoma
- Rhode Island
- South Dakota
- Vermont
- West Virginia
How income shares works in these states:
The paying parent's obligation is calculated as their proportional share of the combined parenting obligation. If the paying parent earns 60% of the combined household income, they pay approximately 60% of the total child support obligation.
This means: the higher the receiving parent's income, the lower the paying parent's obligation (all else equal).
States Using the Percentage of Income Model (~14 States)
These states calculate child support solely based on the paying parent's gross income. The receiving parent's income is not factored into the base calculation.
| State | 1 Child | 2 Children | 3 Children | 4 Children | 5+ Children | |---|---|---|---|---|---| | Texas | 20% | 25% | 30% | 35% | 40% | | Illinois | 20% | 28% | 32% | 40% | 45% | | Wisconsin | 17% | 25% | 29% | 31% | 34% | | Georgia | 17-23% | 25-28% | 29-32% | Varies | Varies | | Minnesota | 25% | 30% | 35% | 37% | 41% | | Mississippi | 14% | 20% | 22% | 24% | 26% | | Nevada | 18% | 25% | 29% | 31% | 34% | | Alabama | 17% | 25% | 29% | 31% | 33% | | Alaska | Varies | Varies | Varies | Varies | Varies | | Iowa | 17.6% | 25.1% | 30.0% | 31.6% | 32.6% | | New Hampshire | 25% | 33% | 40% | 45% | 50% | | North Dakota | 14.35% | 20.4% | 22.4% | 24.35% | 26.35% | | Wyoming | 20% | 28% | 35% | 40% | 40% | | Arkansas | 17% | 25% | 29% | 31% | 34% |
Note: These are simplified representations. States update their guidelines periodically. Always verify current rates with your state's child support agency.
Which Model Is More Favorable for the Paying Parent?
Income Shares tends to be more favorable when:
- The receiving parent earns a significant income
- Both parents earn similar amounts
- The receiving parent earns more than 30% of the paying parent's income
Percentage of Income tends to be more predictable when:
- The receiving parent's income is very low or zero
- The paying parent needs certainty for financial planning
- A simple, consistent formula is preferred
Example comparison — Same paying parent, different models:
Paying parent earns $6,000/month; receiving parent earns $2,000/month; 1 child.
Income Shares model:
- Combined income: $8,000
- State obligation at $8,000 for 1 child: ~$1,200
- Paying parent's share: 6,000/8,000 = 75%
- Monthly payment: $900
Percentage of Income model (17%):
- Paying parent income × 17% = $1,020/month
That's a $120/month difference — or $1,440/year.
State-Specific Notes
Texas
Texas uses the percentage of income model and is one of the most litigated states for child support. Texas caps the income subject to the guideline percentage at a "net resources" ceiling. Courts can deviate upward for high-income earners.
California
California uses income shares and also considers the percentage of time each parent spends with the child (not just primary/shared labels). The state's Dissomaster software is commonly used by family law courts.
New York
New York uses a hybrid: the combined parental income model with a cap. For income up to a certain threshold (around $163,000 combined), standard percentages apply. Income above the cap is handled with judicial discretion.
Florida
Florida uses income shares with an emphasis on overnights. More overnight time with the non-custodial parent reduces the support obligation.
Illinois
Illinois uses percentage of income based on the paying parent's net (after-tax) income, making it different from most states that use gross income.
How to Estimate Your Payment
Use the American Child Support Calculator to get an educational estimate based on your state's model. Enter both parents' incomes (if using income shares) or just the paying parent's income (for percentage states), along with custody arrangement and supplemental expenses.
Remember: our calculator provides a simplified estimate. Your state's actual guidelines use published tables, and courts apply judicial discretion for unusual circumstances.
Frequently Asked Questions
Q: Can I move to a different state to pay less child support? A: Generally no. Child support orders follow federal jurisdiction rules under the Uniform Interstate Family Support Act (UIFSA). You typically cannot unilaterally move to reduce obligations under a different state's formula.
Q: Does my state's model change if both parents have joint custody? A: Custody arrangement is considered separately from the calculation model. Both income shares and percentage states adjust for significant shared custody time.
Q: My state recently changed its guidelines. Does my old order change automatically? A: No. You must file for a modification. A change in guidelines alone doesn't automatically change your order.
Q: What if I live in a state with an unusual income situation? A: Most states allow "deviation" from the guidelines for extraordinary situations. High-earning parents, parents with significant other children, or cases with unusual expenses may warrant a deviation hearing.
This article is for educational purposes only. Child support guidelines change regularly. Always verify current guidelines with your state's child support agency or a licensed family law attorney. This is not legal advice. Find a family law attorney in your state →
Sources: Office of Child Support Services (HHS), individual state child support guidelines, U.S. Census Bureau.