Child Support Arrears: Interest, Enforcement, and What to Do

Arrears are the part of the order that was not paid. They do not expire when the child turns 18 or when the order ends, and in many states they carry interest. That is why an old balance can surface years later, larger than the payments it came from.

Updated November 12, 2026 Sources and methodology

How arrears happen

Each payment that is missed, short, or late becomes past-due support. The order does not warn you and the amount does not adjust itself: a job loss, a gap between paychecks, or a private agreement to pay less all produce the same result, and the difference keeps accumulating until the order is changed.

Missed or partial payments, including a month where overtime disappeared.
Add-ons that were ordered but not reimbursed: childcare, insurance premiums, uninsured medical costs.
A modification filed late, after the income already changed.
Retroactive support in the original order, which starts as arrears on day one.

Interest is state law, not federal

There is no federal interest rate on child support. Some states add a statutory rate to each unpaid installment, some add none, and the rule can be simple or compound, set by statute or by the judgment itself. The rate can also change over the life of the order.

That means two parents with the same unpaid balance in different states can owe very different totals. The statement from the child support agency should show the interest method; if it does not, ask, because interest is the part of a balance most often calculated wrong.

A modification does not erase the balance

A modification changes the amount going forward. The months already missed keep the old figure, and most states limit retroactive reductions. Only a court or the agency can adjust a balance, and usually only for a specific reason such as a payment that was not credited or a mistake in the arithmetic.

This is the same reason the guide to modifying an order stresses the filing date: the new number starts when the request is filed, not when the income changed.

How arrears are collected

Enforcement is mostly automatic once a case is in the agency system. Federal law requires income withholding, and the agency has a wider set of tools when withholding is not enough.

Income withholding from wages, and from some other income such as bonuses.
Tax refund offset, federal and state, for past-due support.
Administrative offset of certain federal payments.
Liens on property and, in some states, on insurance settlements or lottery winnings.
License suspension for driver’s, professional, or recreational licenses.
Credit reporting of the past-due amount.
Contempt in court, which can include jail in the most serious cases.
Passport denial or revocation for large federal arrears.

The federal Office of Child Support Enforcement lists the federal remedies, and each state adds its own.

Check the balance before you pay it

Balances are calculated by systems, and systems make mistakes: a payment posted to the wrong case, a wage withholding that stopped without notice, an add-on charged twice. Ask the agency for a payment history and a breakdown of principal and interest, then compare it with your own records.

Keep receipts, bank statements, and payroll stubs. A canceled check or a bank transfer is often the only evidence that a payment was made, and the burden of proving a payment is usually on the parent who made it.

If you owe

A payment plan is usually better than silence: it stops new enforcement actions, it can release a suspended license, and it shows good faith if the case returns to court. Ask whether the state allows a compromise of interest, and get any agreement in writing before paying.

Bankruptcy is not the shortcut it is for other debts. A domestic support obligation (including support arrears and, under the bankruptcy definition, the interest on them) is not dischargeable. Filing does not make the balance disappear.

If you are owed

Ask the agency to enforce, and ask for the interest calculation. If the case is not in the agency system, a motion to enforce or a judgment for the arrears is the route. Arrears are usually treated as a judgment, which is what allows liens, wage garnishment, and long enforcement periods.

Frequently asked questions

Do child support arrears expire?

Usually not on their own. Most states treat each missed payment as a judgment that can be enforced for years, and many allow enforcement well past the child’s majority. The exact limitation period is state law, so the practical answer is that ignoring an old balance does not make it go away.

Can interest be waived?

Sometimes, but it is not a right. Some states allow the agency or the court to compromise interest or arrears in limited circumstances, and some allow a payment plan instead of a lump sum. The decision usually depends on the state, the age of the balance, and whether the parent is cooperating.

Does a modification stop the arrears?

It stops new arrears from the date the new amount applies. It does not erase the balance that accumulated before. Most states limit retroactive reductions, so the months before you filed keep the old figure, which is why filing early matters more than filing perfectly.

Will the state take my tax refund?

It can. Federal law allows the tax refund offset for past-due support, and states use the same tool for state refunds. Administrative offsets can also intercept other federal payments. If a refund is taken in error, the agency that certified the debt has a dispute process, and it has a deadline.

Sources.

Figures are estimates for the basic obligation and are not legal advice. The court’s order controls. See the methodology and update policy.

Written and maintained by Jesús Muentes.

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