What's in an arrears answer
Each state page explains what unpaid child support becomes in that state, whether the state charges interest on it and how, and how long the debt can be collected, then lets you add up what is owed. Every legal figure is tied to a cited source; see our methodology for how we verify each one.
Unpaid support is a judgment
Under federal law (42 U.S.C. 666(a)(9)), every child support payment or installment, once it is due, is a judgment by operation of law, with the full force and effect of a judgment of the state and entitled to full faith and credit in every other state. A missed payment therefore does not disappear: it stays a debt, and it cannot be reduced retroactively except from the date notice of a petition to modify was given.
Interest is a state decision
Whether unpaid support also earns interest is not set federally. The National Conference of State Legislatures keeps a state-by-state survey of interest on child support arrears showing that most jurisdictions authorize interest and a minority do not, and that those that do differ on three points:
- The rate — a fixed annual percentage in some states, a monthly rate in others, and a rate tied to the market or to the state's judgment rate in others.
- The method — simple interest on the unpaid principal in some states and compound interest in others.
- Who triggers it — automatic in some states, only when a judge orders it or a party asks in others, and sometimes waivable by the parent owed support or by the state agency.
Because rates and rules change, each state page cites the current statute or rule it relies on and shows a dollar figure only where that law sets a rate.