Interest on child support arrears generally belongs to the custodial parent. It is paid to compensate that parent for money that should have arrived on time, and state enforcement agencies collect it on the parent’s behalf. The main exception involves public assistance: when the custodial parent received Temporary Assistance for Needy Families (TANF), part of the interest is kept by the state and federal government to reimburse what they paid out. Where the parents live in different states, which rate applies is a separate question from who receives the money, and taxes take another bite before the parent sees what is left.
Why the Custodial Parent Is the Default Recipient
Interest on arrears exists to compensate the custodial parent for the time value of money they should have received on schedule. It is not a fine or penalty imposed on the noncustodial parent for the state’s benefit. The legal framework in most jurisdictions treats accrued interest as belonging to the custodial parent, and about 34 states authorize interest at annual rates typically ranging from 4% to 12%, most commonly 6%.1NCSL. Interest on Child Support Arrears Most of those states use simple interest; a smaller group allows compounding, which can grow a balance much faster at the same stated rate.
Why It Still Takes a While to Reach You
Entitlement and timing are two different things. Even when the interest is legally yours, where a payment lands depends on the allocation order used by your state agency. The standard approach pays current support first, then applies anything left to the arrears principal, and only after that does money flow toward accrued interest.
In practice, if the noncustodial parent is barely keeping up with current support, it can take years before any payment touches the interest balance. The money has your name on it. It just sits at the back of the line.
When the State Keeps Part of the Interest
The biggest exception to the custodial-parent rule involves TANF. A custodial parent who receives TANF must assign their child support rights to the state as a condition of benefits.2The Administration for Children and Families. TANF-ACF-PI-2007-02 Questions and Responses on Coordination Between the TANF and the Child Support Enforcement Programs That assignment covers arrears that accumulate during the period of assistance, and the interest on those arrears follows the same path.
Under federal distribution rules, when a family is currently receiving TANF and a child support collection comes in, the state and federal government reimburse themselves for the assistance paid before the family receives any surplus. Once the family stops receiving assistance, collections on arrears that weren’t assigned during the TANF period go to the family first. But for the assigned portion, the state and federal government still take their share to recoup what they paid out, capped at the total amount of assistance actually provided to the family.3Office of the Law Revision Counsel. 42 U.S. Code 657 – Distribution of Collected Support
So the practical answer, if you received TANF while arrears were building: a significant chunk of what eventually gets collected on those arrears, including interest, may go to reimburse the government rather than into your pocket. Arrears (and interest on them) that accumulated before or after your TANF period remain yours.
There is a related limit on who can forgive what. States can compromise arrears that were assigned to them during TANF periods. But arrears owed directly to the custodial family can only be forgiven by the custodial parent, not by the state. Some states offer interest-waiver incentives tied to consistent payment under a plan, which may compromise previously accrued interest the state is owed.4Administration for Children & Families. State Child Support Agencies with Debt Compromise Policies
Interstate Cases: Whose Rate Applies, Who Still Gets Paid
When a child support order was issued in one state but the noncustodial parent now lives in another, the Uniform Interstate Family Support Act (UIFSA) controls. Under UIFSA Section 604, the law of the state that issued the original support order governs the computation and accrual of interest on arrears.5Administration for Children and Families. Interstate Child Support Policy If you have a Texas order and the noncustodial parent moved to a state with no interest provision, interest still accrues at the Texas rate.
Who receives the interest does not change because of distance. It is still the custodial parent, subject to the same TANF rules if assistance was involved. The enforcement procedures follow the law of the state where the order is registered for enforcement, and for statutes of limitation, UIFSA applies the longer of the two states’ limitations periods.5Administration for Children and Families. Interstate Child Support Policy
What You Actually Keep: The Tax Hit
This is the part that catches people off guard. Child support payments themselves are not taxable income to the recipient and are not deductible by the payor.6Internal Revenue Service. Publication 525 (2025), Taxable and Nontaxable Income Interest on arrears is treated differently. The IRS classifies interest received on past-due child support as taxable interest income, the same as interest from a bank account. Courts have consistently held that because interest compensates for delay in receiving funds, it is taxable regardless of whether the underlying principal is taxable.
If the interest paid to you in a given year exceeds the reporting threshold, your state child support agency will issue a Form 1099-INT for the amount, and you must report it on your federal return. If a lump-sum interest payment arrives after years of arrears collection, the tax hit can be substantial in a single year.
The Payor Cannot Erase What You Are Owed
Noncustodial parents sometimes consider bankruptcy as a way to escape mounting arrears. It will not work for child support. The Bankruptcy Code defines “domestic support obligation” to explicitly include interest that accrues on support debts under applicable state law.7Office of the Law Revision Counsel. 11 U.S. Code 101 – Definitions Domestic support obligations are non-dischargeable in Chapter 7, Chapter 13, or Chapter 11.8Office of the Law Revision Counsel. 11 U.S. Code 523 – Exceptions to Discharge A filing can pause collection temporarily through the automatic stay, but the debt (and the interest on it) remains fully enforceable afterward.
The underlying principal is similarly locked in. The federal Bradley Amendment makes every missed child support payment an automatic judgment the moment it comes due, and these judgments cannot be retroactively modified.9Office of the Law Revision Counsel. 42 USC 666 – Requirement of Statutorily Prescribed Procedures to Improve Effectiveness of Child Support Enforcement A court may modify future payments if circumstances change, but arrears already accrued are fixed. Interest on those locked-in arrears is a separate question and is subject to greater judicial discretion, so a payor who shows genuine hardship with real documentation may get interest reduced or waived.
Don’t Let Time Run Out on Interest You Are Owed
The underlying child support obligation is generally not subject to expiration in most states, but the ability to collect interest on arrears may be time-limited depending on where the order was issued. Some states set a window of 10 to 20 years from when the arrears were established or the most recent payment was made. Others treat interest as part of the overall judgment with no separate limitations period.
For interstate cases, UIFSA again applies the longer of the two states’ limitations periods, and some states toll the clock when the noncustodial parent is out of state or concealing their location.5Administration for Children and Families. Interstate Child Support Policy A noncustodial parent can raise the statute of limitations as a defense to avoid paying aged interest, so a custodial parent who waits too long may lose the right to collect. If you have old arrears with interest accruing and have not taken enforcement action, checking your state’s limitations period should be the next thing you do.