Back child support in California is past-due court-ordered support that accrues simple interest at 10% per year under Cal. Code Civ. Proc. § 685.010, with no statute of limitations on collection. As of June 2026, the California Department of Child Support Services (DCSS) enforces arrears through wage garnishment of up to 50-65% of disposable income, tax intercepts, license suspension, and passport denial. Child support debt survives the child reaching adulthood and cannot be waived, even by mutual agreement of both parents.
This guide explains how arrears accumulate, what enforcement tools DCSS uses, how the 10% interest rate compounds your child support debt over time, and the limited circumstances under which past due child support can be reduced through the Compromise of Arrears Program. Whether you owe child support or are owed it, understanding California Family Code enforcement rules helps you protect your rights and avoid escalating penalties.
Key Facts: Back Child Support in California
| Factor | California Rule |
|---|---|
| Interest Rate on Arrears | 10% simple interest per year (Cal. Code Civ. Proc. § 685.010) |
| Statute of Limitations | None — arrears are enforceable indefinitely |
| Can Arrears Be Waived? | No — not even by agreement of both parents |
| Wage Garnishment Limit | 50% (supporting another family) up to 65% of disposable income |
| License Suspension Trigger | 30 days delinquent (Cal. Fam. Code § 17520) |
| Passport Denial Threshold | $2,500 in arrears (42 U.S.C. § 652(k)) |
| DCSS Application Cost | Free; $35 annual service fee after $500 collected |
| Debt Reduction Program | COAP (government-owed arrears only, $501 minimum) |
What Counts as Back Child Support in California?
Back child support in California is any court-ordered child support payment that was not paid by its due date, converting automatically into a money judgment called arrears. Each missed payment becomes a separate debt the moment it goes unpaid, and California treats these arrears as enforceable judgments under Cal. Fam. Code § 4502. Unlike most debts, child support arrears do not require the receiving parent to file a new lawsuit to collect.
Arrears fall into two categories that determine your options for relief. Arrears owed to a custodial parent represent support that should have gone directly to the child's household and cannot be reduced through any state program. Arrears owed to the government accrue when a child received public assistance such as CalWORKs or foster care while support went unpaid, and the state seeks reimbursement. This distinction matters because only government-owed child support debt qualifies for the Compromise of Arrears Program. Past due child support continues accruing regardless of the parent's employment status, incarceration, or inability to pay, unless the order is formally modified by a court.
How Much Interest Does Back Child Support Accrue in California?
Back child support in California accrues simple interest at exactly 10% per year under Cal. Code Civ. Proc. § 685.010, the second-highest child support interest rate in the nation according to the National Conference of State Legislatures. This 10% rate is mandatory, applies from the date each payment becomes due, and a California judge has no legal authority to waive or reduce accrued interest, even when both parents agree.
Because the interest is simple rather than compounding, it calculates against the principal balance only. If a parent misses a $1,000 payment, after one year that single missed payment grows by $100 in interest, raising the total to $1,100. When a parent makes a partial payment toward arrears, California applies that payment first to the principal balance and then to accrued interest. Over a decade of unpaid child support, this 10% rate can nearly double the original child support debt. For example, $20,000 in principal arrears left unpaid for ten years accumulates approximately $20,000 in additional simple interest, creating a $40,000 total obligation. This is why addressing past due child support early prevents the debt from spiraling beyond a parent's ability to repay.
Is There a Statute of Limitations on Back Child Support in California?
There is no statute of limitations on back child support in California — arrears remain enforceable until every dollar of principal and interest is paid in full. A child support obligation survives the child turning 18, graduating from college, becoming emancipated, and in some circumstances even the death of the receiving parent. California treats child support arrears as judgments that are renewable indefinitely under Cal. Fam. Code § 4502.
This permanence makes California child support debt fundamentally different from ordinary civil debts, which typically become unenforceable after four to ten years. A custodial parent or DCSS can pursue collection of child support arrears 10, 20, or even 30 years after the arrears first accrued. Adult children who never received support owed to them may, in some cases, still trigger enforcement against the owing parent. The California Court of Appeal reinforced this rule in its February 2026 decision in In re Marriage of Allen, which confirmed that California law prevents parents from contractually waiving or forgiving past due child support arrearages, even after the child has become an adult. The only way to extinguish back child support is to pay it in full or, for government-owed portions, negotiate a reduction through COAP.
How Does California Enforce Back Child Support?
California enforces back child support through the Department of Child Support Services, which deploys wage garnishment, tax refund intercepts, license suspension, property liens, bank levies, and passport denial — often simultaneously. Wage garnishment is the primary tool, withholding up to 50% of disposable income when the obligor supports another family, or up to 65% when arrears exceed 12 weeks. Employers must implement a wage assignment within 10 days of receiving the order.
Multiple enforcement mechanisms can strike at the same time, and the pressure increases as the child support debt grows. The following table summarizes the primary DCSS enforcement tools and their thresholds as of June 2026:
| Enforcement Tool | Trigger / Threshold | Authority |
|---|---|---|
| Wage garnishment | Any arrears; up to 50-65% of disposable income | Federal CCPA limits |
| Driver's/professional license suspension | 30 days delinquent | Cal. Fam. Code § 17520 |
| Federal tax refund intercept | $150+ in arrears | 42 U.S.C. § 664 |
| State tax refund intercept | Any past-due balance | DCSS policy |
| Credit bureau reporting | $1,000+ in arrears | Monthly reporting |
| Passport denial | $2,500+ in arrears | 42 U.S.C. § 652(k) |
| Bank account levy | Any arrears | DCSS levy authority |
License suspension under Cal. Fam. Code § 17520 is among the most disruptive tools because it can affect driver's licenses, professional licenses, and recreational licenses. After 30 days of delinquency, DCSS sends advance notice of potential suspension, and reinstatement generally requires either full payment or a formal repayment agreement. Wage garnishment follows the obligor across employers — when a parent changes jobs, DCSS issues a new wage assignment to the new employer, creating continuous enforcement throughout the parent's working life.
Can You Reduce Back Child Support in California Through COAP?
You can reduce back child support in California only when the arrears are owed to the government, through the Compromise of Arrears Program (COAP), which requires a minimum of $501 in state-owed debt. COAP lets eligible noncustodial parents offer a partial payment — based on income and assets — in exchange for forgiving a portion of arrears and interest owed to the state. COAP cannot reduce any child support debt owed to a custodial parent.
To qualify for COAP in 2026, a parent generally must owe at least $501 in government-owed arrears, lack the ability to pay the full balance plus interest within three years of applying, and have no conviction or contempt finding for failure to pay support within the six months before applying. The program allows repayment either as a lump sum or through monthly payments over up to 36 months. Compliance is strict: a parent must keep current on ongoing support throughout the agreement, and missing payments triggers a rescission that restores the full pre-agreement arrears balance with no refund for amounts already paid. A rescinded agreement also bars reapplication for two years. Several counties, including Butte County, have introduced expanded Debt Reduction Programs that broaden COAP eligibility, so contacting your Local Child Support Agency directly is the best way to confirm current options.
How Do You Collect Back Child Support You Are Owed in California?
You collect back child support you are owed in California by opening a case with the Department of Child Support Services, which provides free establishment, modification, and enforcement services under fee-waiver provisions in Cal. Gov. Code § 6103.9. There is no cost to apply, though DCSS charges a $35 annual service fee once it has collected $500 or more on your behalf in a federal fiscal year (October 1 to September 30).
After opening a case, DCSS calculates the total arrears owed, including accrued 10% interest, and pursues collection using its full enforcement toolkit. Custodial parents may also enforce arrears privately by obtaining a judgment of arrearages from family court and using post-judgment collection methods such as wage assignments, abstracts of judgment recorded as property liens, and bank levies. Because back child support carries no statute of limitations, a parent can pursue collection even decades after the arrears accrued. Families receiving CalWORKs benefits automatically have a DCSS case opened on their behalf at no cost, with the agency required by law to pursue establishment and collection. For parents with complex arrears calculations or interstate enforcement issues, consulting a California family law attorney ensures the full principal and 10% interest are accurately captured before the debt is reduced to a formal judgment.
What Happens to Back Child Support When the Child Turns 18?
Back child support in California does not disappear when the child turns 18 — accrued arrears remain fully enforceable as a money judgment, and the 10% annual interest continues to accumulate until the entire balance is paid. While the obligation to pay current ongoing support generally ends when a child reaches 18 (or 19 if still a full-time high school student living at home), any unpaid balance from earlier years survives indefinitely.
This means a parent who fell behind during the child's minor years still owes every dollar of principal plus a decade or more of compounded simple interest after the child becomes an adult. The California Court of Appeal's February 2026 ruling in In re Marriage of Allen confirmed that parents cannot waive or forgive these adult-era arrears, even by written agreement. DCSS and custodial parents retain full enforcement power — including wage garnishment, tax intercepts, and license suspension — to collect arrears that built up while the child was a minor. The permanence of California child support debt underscores why parents who anticipate falling behind should seek a court modification of the support order before arrears accumulate, since modification only affects future payments and never retroactively reduces past due child support.
What Should You Do If You Can't Pay Child Support in California?
If you can't pay child support in California, file a request to modify your support order immediately, because modification only affects future payments and a court cannot retroactively reduce arrears that have already accrued. California courts may adjust a child support order when there is a significant change in circumstances such as job loss, disability, incarceration, or a substantial income reduction, but the change takes effect only from the filing date forward.
Waiting to act allows arrears to accumulate at the 10% interest rate while exposing you to wage garnishment, license suspension under Cal. Fam. Code § 17520, and other enforcement. DCSS offers free modification services, and there is no filing fee for modifications processed through the agency under Cal. Gov. Code § 6103.9. If you already owe government-held arrears you cannot repay, the Compromise of Arrears Program may reduce the state-owed portion based on your ability to pay. Setting up a voluntary repayment plan with your Local Child Support Agency before delinquency reaches 30 days can also prevent license suspension. The worst response is inaction: ignored child support obligations grow relentlessly because California law provides no statute of limitations and no automatic forgiveness for past due child support.