How Child Support Is Calculated, and How to Change It
This guide is general information, not legal advice. Laws differ from state to state and change over time. For advice about your situation, talk to a licensed lawyer in your state.
Both parents have a legal duty to support their children. When parents live apart, a court or state agency usually sets a child support amount that one parent pays to the other. Every state uses written guidelines, so the result is more predictable than many parents expect.
The main guideline models
- Income shares: used by most states. The court estimates what the parents would have spent on the child if they lived together, then divides that amount according to each parent’s share of the combined income.
- Percentage of income: used by a smaller number of states. Support is a set percentage of the paying parent’s income, depending on the number of children.
- Melson formula: a more detailed version of income shares used in a few states, which first sets aside a basic amount for each parent’s own needs.
Most states publish an official child support calculator or worksheet online.
What goes into the calculation
- Each parent’s income, which can include wages, self-employment income, bonuses and some benefits
- The number of children
- How much time the children spend with each parent
- Health insurance and uninsured medical costs
- Child care costs related to work or school
- Support paid for children from other relationships
If a parent is voluntarily unemployed or underemployed, a court may “impute” income based on what they could reasonably earn.
Departing from the guidelines
Courts generally must follow the guideline amount unless there is a good reason to depart from it, such as a child’s special needs or very high parental income, and they usually must explain the reason in writing.
How support is collected and enforced
Support is often paid through automatic wage withholding. If a parent falls behind, states have strong enforcement tools, which can include intercepting tax refunds, suspending driver’s and professional licenses, reporting to credit bureaus, placing liens on property and, in some cases, contempt of court. Federal rules also allow passport denial when arrears are high.
Each state has a child support agency that can help establish paternity, set up an order and enforce it, for little or no cost.
Changing a child support order
Either parent can ask to modify support when there is a significant change in circumstances, such as a job loss, a substantial raise, a change in custody or new medical needs. Important points:
- Act quickly. In general, past-due child support cannot be reduced retroactively. A change usually applies only from the date you filed your request, so file as soon as your situation changes.
- Informal agreements are risky. If parents agree to a different amount without a court order, the original order is usually still enforceable.
- Periodic reviews. Many states let parents request a review every few years even without a major change.
When support ends
Support usually ends when the child turns 18 or finishes high school, though some states extend it longer, and support may continue for an adult child with a disability. Past-due support does not end when the child grows up.
Do you need a lawyer?
Many parents handle straightforward support cases through the state agency or court self-help centers. A family lawyer is helpful if income is hard to determine, such as with self-employment, if custody is also disputed, or if the other parent has a lawyer.
Find a Family Law lawyer near you
Browse Family Law lawyers on NearLawyers, or choose your state to see lawyers grouped by city. You can also search by legal issue and location from the home page. Searching and contacting lawyers through NearLawyers is free.
