Child support by state varies significantly across the United States. While federal law requires every state to maintain child support guidelines, each state sets its own formula, income definitions, age of termination, and enforcement tools. The vast majority of states use the income shares model, which bases support on both parents’ combined income. A few states use the percentage of income model, and three states use the Melson formula. This 50-state comparison guide shows the key child support features in every state.
Click any state name below to read its detailed child support guide with calculation formulas, modification rules, and enforcement tools.
Quick Facts — U.S. Child Support by State (2026)
- 41 states use the Income Shares formula — support based on both parents’ combined income
- 4 states use the Percentage of Income model (Mississippi, Nevada, Texas, Wisconsin)
- 3 states use the Melson formula (Delaware, Hawaii, Montana) — accounts for parents’ basic needs first
- Support ends at age 18 in most states, but ranges from 18 to 21 depending on the state
- 14 states allow courts to order college support contributions
- Every state has a child support enforcement agency that can garnish wages, suspend licenses, and intercept tax refunds
All 50 States — Child Support Comparison
The table below shows each state’s child support formula model, age when support ends, whether college support can be ordered, and notable features. Click any state name to read the full guide.
| State | Formula Model | Age Ends | College Support | Notable |
|---|---|---|---|---|
| Alabama | Income Shares | 19 | No | Terminates at 19, not 18 |
| Alaska | Income Shares | 18 | No | High cost-of-living adjustments |
| Arizona | Income Shares | 18 | No | Shared parenting time offsets |
| Arkansas | Income Shares | 18 | No | Chart-based guidelines |
| California | Income Shares | 18 | No | Complex statewide formula |
| Colorado | Income Shares | 19 | No | Online calculator available |
| Connecticut | Income Shares | 18 | Yes | College support to age 23 |
| Delaware | Melson | 18 | No | One of 3 Melson formula states |
| Florida | Income Shares | 18 | No | Detailed guidelines schedule |
| Georgia | Income Shares | 18 | No | Deviation factors considered |
| Hawaii | Melson | 18 | Yes | Melson formula, college support |
| Idaho | Income Shares | 18 | No | Percentage-based guidelines |
| Illinois | Income Shares | 18 | Yes | College support ordered by court |
| Indiana | Income Shares | 19 | Yes | College support, terminates at 19 |
| Iowa | Income Shares | 18 | Yes | Post-secondary support available |
| Kansas | Income Shares | 18 | No | Administrative process available |
| Kentucky | Income Shares | 18 | No | Shared custody offset formula |
| Louisiana | Income Shares | 18 | No | Deviation for extraordinary expenses |
| Maine | Income Shares | 18 | No | Shared parenting adjustment |
| Maryland | Income Shares | 18 | No | Combined income schedule |
| Massachusetts | Income Shares | 18 | Yes | College support to age 23 |
| Michigan | Income Shares | 18 | No | State formula with medical add-on |
| Minnesota | Income Shares | 18 | No | Parenting expense adjustment |
| Mississippi | Percentage | 21 | No | Percentage of income model, age 21 |
| Missouri | Income Shares | 18 | Yes | College support to age 22 |
| Montana | Melson | 18 | No | One of 3 Melson formula states |
| Nebraska | Income Shares | 19 | No | Terminates at 19 |
| Nevada | Percentage | 18 | No | Percentage of income model |
| New Hampshire | Income Shares | 18 | No | Shared placement adjustments |
| New Jersey | Income Shares | 19 | Yes | College support, terminates at 19 |
| New Mexico | Income Shares | 18 | No | Gross income based |
| New York | Income Shares | 21 | Yes | Terminates at 21, college support |
| North Carolina | Income Shares | 18 | No | Guidelines schedule |
| North Dakota | Income Shares | 18 | No | Percentage-based schedule |
| Ohio | Income Shares | 18 | No | Administrative process available |
| Oklahoma | Income Shares | 18 | No | Shared parenting computation |
| Oregon | Income Shares | 18 | No | Child care and medical factored |
| Pennsylvania | Income Shares | 18 | No | Combined adjusted net income |
| Rhode Island | Income Shares | 18 | No | Combined income guidelines |
| South Carolina | Income Shares | 18 | Yes | College support to age 22 |
| South Dakota | Income Shares | 18 | No | Net income guidelines |
| Tennessee | Income Shares | 18 | No | Worksheet-based calculation |
| Texas | Percentage | 18 | No | Percentage of net resources |
| Utah | Income Shares | 18 | No | Combined gross income table |
| Vermont | Income Shares | 18 | No | Gross income calculation |
| Virginia | Income Shares | 18 | No | Combined gross income schedule |
| Washington | Income Shares | 18 | Yes | Post-secondary support available |
| West Virginia | Income Shares | 18 | No | Shared parenting formula |
| Wisconsin | Percentage | 18 | No | Percentage of income model |
| Wyoming | Income Shares | 18 | No | Net income guidelines |
Understanding How Child Support Differs by State
The Income Shares model, used by the majority of states, calculates support based on both parents’ combined adjusted gross income and the number of children. The model estimates what the parents would have spent on the children if the household were intact, then divides that amount proportionally based on each parent’s share of the combined income. Parenting time adjustments reduce the non-custodial parent’s obligation in many states when they have significant overnight time.
The Percentage of Income model, used by Texas, Wisconsin, Nevada, and Mississippi, calculates support as a flat percentage of the non-custodial parent’s income. This is simpler but does not account for the custodial parent’s income. The Melson formula, used by Delaware, Hawaii, and Montana, adds an additional step by first deducting each parent’s basic living needs before calculating the support amount.
College Support — A Major State Difference
Whether a court can order parents to contribute to college costs is one of the most significant differences between states. 14 states currently allow courts to order post-secondary education support: Connecticut, Hawaii, Illinois, Indiana, Iowa, Massachusetts, Missouri, New Jersey, New York, South Carolina, and Washington, among others. In these states, courts consider the parents’ financial resources, the child’s academic ability, and the cost of the institution.
In states that do not allow court-ordered college support, parents can still agree to contribute voluntarily as part of their divorce settlement or separation agreement. Including college provisions in the original divorce agreement is strongly recommended in all states.
Find Your State Child Support Guide
Ready to understand your state’s child support rules? Click any state name in the table above, or browse by topic using the links below.
Official Sources
- OCSE: acf.hhs.gov/css — Office of Child Support Enforcement
- Cornell LII: law.cornell.edu — Child support legal information
- NCSL: ncsl.org — National Conference of State Legislatures
State data compiled from official state DCSS agencies, OCSE federal data, and state statutes. Guideline amounts and formulas are subject to legislative changes. Click any state name above for your complete state guide. Last reviewed April 2026.