Unpaid Child Support in California: What the Law Allows and What Happens Next

Most people facing unpaid child support in San Diego County come to this question from one of two sides. One parent has watched payments slow or stop and is trying to figure out what the law can actually make happen. The other parent has fallen behind after a job loss or a pay cut, and is worried about jail, a suspended license or a debt that keeps growing. Both are trying to understand the same set of rules before deciding what to do. For many of them, the dispute has stopped being a simple billing problem and become a contested matter headed for the Superior Court of California, County of San Diego.

This article walks through how arrears build up, which enforcement tools California law authorizes, how contempt works, what happens when the child turns 18, how a support order is changed, what the 2024 guideline changes mean, and what local resources exist.

Arrears are the past-due balance. They are every payment the court ordered that was not made in full and on time. In California, each missed installment generally becomes a judgment on the date it falls due, without anyone going back to court to ask for it. That is why an arrears balance can grow quietly for months or years.

It helps to separate two things that people often blend together:

• The current support order is the monthly amount going forward. It can be changed by the court.
• The arrears balance is what already came due and went unpaid. It is treated as a debt that already exists.

Interest is the next piece. Under Code of Civil Procedure section 685.010, "interest accrues at the rate of 10 percent per annum on the principal amount of a money judgment remaining unsatisfied." The statute sets a lower 5 percent rate only for certain medical-expense and personal-debt judgments, so child support arrears generally accrue at 10 percent. Over several years, interest can become a large share of what is owed.

Arrears also do not expire. Family Code section 291 says a support judgment "is enforceable until paid in full or otherwise satisfied," and it is exempt from the usual requirement that judgments be renewed. Family Code section 4500 adds that a support order made, entered, or enforceable in California is enforceable under the Family Code, regardless of whether it was originally made or entered under this code.

When a local child support agency is enforcing the case, Family Code section 17523 creates a lien. A lien is a legal claim against property. It attaches to the obligor's personal property for overdue support by operation of law, meaning automatically, and it can be perfected by filing a notice with the California Secretary of State. In San Diego County, these cases are heard by the Superior Court of California, County of San Diego.

Family Code section 290 sets the outer boundary. It says a family law judgment or order may be enforced "by execution, the appointment of a receiver, or contempt, or by any other order as the court in its discretion determines from time to time to be necessary." That is a broad grant of power, and support orders sit at its center.

Earnings assignment. This is the most common tool. An earnings assignment order for support directs the paying parent's employer to send part of each paycheck to the parent who receives support. Under Family Code section 5230, when the court orders support or modifies it, the court "shall include in its order an earnings assignment order for support." That amount covers both the current support and an amount toward any arrearage. The order is effective even if the obligor's employer is not yet known. Because it is built into the support order, it is generally in place from the start, subject to limited exceptions the law allows. It is served on the employer as an income withholding order.

Tax refund intercepts. State and federal tax refunds can be intercepted and applied to arrears through programs run with the California Department of Child Support Services.

License actions. Family Code section 17520 sets out California's license-related enforcement for support. It covers a long list of licensing bodies, including the Department of Motor Vehicles, the State Bar of California, the Department of Real Estate, the Secretary of State and the Department of Fish and Wildlife. That reaches driver's licenses, many professional and business licenses, and some recreational licenses.

Passport denial. Federal law allows a U.S. passport to be denied or revoked when child support arrears pass a threshold set under federal law.

Levies and liens. Bank accounts can be levied, which means seized to pay the debt. Liens can attach to property, including the section 17523 personal-property lien described above.

Contempt. Contempt of court is the court's power to sanction a person who willfully disobeys its order. It is covered in its own section below.

The San Diego County Department of Child Support Services (DCSS) is the local agency that runs much of this enforcement. A parent owed support may work through DCSS, bring a private enforcement action in the Superior Court of California, County of San Diego, or do both. The San Diego County support disputes overview covers how these cases are set and enforced locally.

Contempt is the remedy behind the question "can someone go to jail for this?" The answer is yes. But it is not automatic, and the law puts real requirements in front of it.

A contempt case in family court is started by a filing and an order to show cause. That is an order requiring the person accused to appear and explain why they should not be held in contempt. Then a hearing follows in the Superior Court of California, County of San Diego. The person accused has the right to answer the charge. The party bringing contempt generally has to show that a valid order existed, that the other person knew about it, and that they had the ability to comply and willfully did not. A parent who truly could not pay is generally not in contempt. Inability to pay is a recognized defense.

The penalties come from Code of Civil Procedure section 1218. On a finding of contempt, "a fine may be imposed on the person not exceeding one thousand dollars ($1,000), payable to the court, or the person may be imprisoned not exceeding five days, or both." The court may also order the person in contempt to pay the other party's reasonable attorney's fees and costs for the contempt proceeding.

Two rules from Code of Civil Procedure section 1218.5 shape support contempt. First, each month for which payment was not made in full may be charged as a separate count, with punishment for each count proven. Second, a contempt action for unpaid support must be started within three years from the date the payment was due. That is a deadline on the contempt remedy only. The debt itself remains collectible under section 291.

Courts generally distinguish two kinds of contempt. Civil contempt is coercive. It is meant to push someone to comply, and it ends when they do. Criminal contempt is punitive. It punishes a past violation. The procedural protections differ between the two. The step-by-step guide to contempt in family court walks through the filing and hearing process in more detail.

Separate from contempt, Penal Code section 270 makes it a crime for a parent to willfully omit, "without lawful excuse," to furnish necessary food, clothing, shelter, medical attendance or other remedial care for a minor child. It is a misdemeanor punishable by a fine of up to $2,000, county jail of up to one year, or both. Where a court has already found the person is the child's parent and the person knew it, the conduct can carry up to one year in county jail or a state prison term of one year and one day, a fine of up to $2,000, or both. That is a criminal prosecution, not a family court motion. The article on jail for unpaid child support explains why no arrears figure automatically leads there.

A parent behind on support often reads this section with a knot in the stomach. In contempt proceedings, willfulness and ability to pay are the central legal questions; the facts about income and effort are therefore central to how courts evaluate these cases.

The ongoing duty to pay support and the debt for past support are two different things, and they end on different schedules.

The ongoing duty can end around adulthood. Under Family Code section 3901, the support duty continues for an unmarried child who has turned 18, is a full-time high school student and is not self-supporting, "until the time the child completes the 12th grade or attains 19 years of age, whichever occurs first." A child with a medical condition documented by a physician that prevents full-time attendance is excused from the full-time student requirement. Parents may also agree to provide more support.

The arrears do not end with the child's birthday. Section 291, discussed above, keeps a support judgment enforceable until it is paid in full, with no renewal needed. Interest under section 685.010 keeps accruing on the unpaid principal. The enforcement tools stay available too, including earnings assignments, tax intercepts and liens. San Diego County DCSS continues to assist with collecting arrears after the current support obligation has ended.

So a parent who was owed support for years, and whose child is now grown, is still dealing with a live debt. A parent who stopped paying when a child aged out may still owe everything that came due before that point.

Family Code section 3651 gives the court power to change support: "a support order may be modified or terminated at any time as the court determines to be necessary." In practice, a request to modify generally rests on a change in circumstances since the last order. Common examples include a significant change in either parent's income, a job loss, a disability, or a change in how much time the child spends with each parent.

The timing rule matters most for a parent who is falling behind. Section 3651 says a support order generally "may not be modified or terminated as to an amount that accrued before the date of the filing of the notice of motion or order to show cause to modify or terminate." Put plainly, a modification works forward from the filing date. Support that came due before then generally stays owed.

Family Code section 3653 fills in the retroactivity rules. A modification may reach back to the date the request was filed, or to a later date. When the change is based on unemployment, the order is made retroactive to the later of the date the other party was served or the date of unemployment, unless the court finds good cause not to and states its reasons on the record.

The practical result is direct. Simply not paying does not reduce the order, and it does not protect against enforcement or contempt. The court changes support only after a request is filed. Contested modification fights often turn on income, including whether one parent's true earnings are being reported. The guide on how to prove hidden income covers the disclosure and discovery tools used in those disputes.

For arrears owed to the state rather than to the other parent, such as support assigned to the government, California's Debt Reduction Program may offer a way to reduce the state-owed balance. It does not apply to arrears owed directly to the other parent. Current program details are posted at childsupport.ca.gov. The article on whether child support arrears can be forgiven explains the limits on erasing support that has already come due.

Searches for a "new child support law" in 2026 usually point back to changes to California's guideline that took effect September 1, 2024. That is a 2024 change, and it carries into the cases being decided in 2025 and 2026.

The guideline itself lives in Family Code section 4055. The formula reads: "CS = K[HN - (H%)(TN)]." In plain terms, it starts with each parent's net monthly disposable income, meaning income after the deductions the law allows. Then it weighs the percentage of time the higher earner has primary physical responsibility for the children. Those numbers produce a guideline amount. Courts run the formula through certified software, not by hand.

The 2024 revisions changed how the guideline treats lower-income parents and adjusted parts of the calculation. Three points tend to matter most:

• Existing orders do not change on their own. A parent has to file a request to modify before the revised guideline is applied to that case.
• Existing arrears are not affected. The update does not reduce what already came due.
• Older orders may be worth reviewing. Orders set before September 2024 may be subject to recalculation under the revised guideline if a party files a request to modify; whether the new figure would be higher or lower depends entirely on that family's numbers.

Several public resources serve both sides of a support case in San Diego County.

• San Diego County Department of Child Support Services. DCSS provides free enforcement services for parents owed support, including earnings assignments, intercepts and liens. Information is at sandiegocounty.gov/content/sdc/dcss.
• California Department of Child Support Services. The statewide portal at childsupport.ca.gov offers case information, payment options and program details, including the Debt Reduction Program.
• Court self-help. The Superior Court of California, County of San Diego, has a Family Law Facilitator's Office, and the Judicial Council's California Courts Self-Help Guide explains support, modification and enforcement.

A private family law action in the Superior Court of California, County of San Diego, is a separate path. It can run alongside a DCSS case. A private action is where a parent can bring contempt, ask to modify an order, and press issues that agency enforcement does not take on, such as disputes over private agreements or support questions tied up with a contested custody case. When support and parenting time are fought over together, the overview of contested child custody explains how custody issues move through court. The timeshare in a custody order also feeds directly into the guideline formula. San Diego Family Law Advocates practices California family law only. Within that practice, private counsel can prepare and argue contempt, modification and enforcement matters in court.

Support enforcement and modification cases usually turn on a few concrete facts. These include the exact terms and dates of the current order, what has been paid and when, whether arrears are owed to the other parent or to the state, and the paying parent's real ability to pay. A consultation is a place to raise those facts, ask how sections 291, 3651 and 1218 may apply, and discuss whether DCSS, a private court action, or both may fit the situation. For readers on either side of the case, the conversation can also cover whether the September 2024 guideline changes bear on an older order.

To talk with the firm about unpaid child support, call San Diego Family Law Advocates at 858-758-2288 for a confidential consultation.