Can You Get Retroactive Child Support in California?

California parents have a legal duty to support their children until the kids turn 18 (or 19 if they're still in high school). When parents get divorced, one of them will almost always have to make child support payments to the other. Judges may also order unmarried parents to pay support for their children.

Either way, a child support order may be retroactive—meaning it applies to a period before the order was issued. Read on to learn how retroactive child support works in California.

What's the Difference Between Retroactive Child Support and Arrearages?

Retroactive child support is not the same as child support arrearages. When a judge orders a parent to pay retroactive child support, the parent will owe support for a certain period of time before the date of the order. Child support arrearages (sometimes called "arrears" or "back" support) is the legal term for any amounts a parent hasn't paid under an existing support order.

California law sets strict limits on how far back retroactive child support can go (more on that below).

In contrast, there are generally no time limits on collecting child support arrearages. A parent who owes back support may have to pay the arrearages even after the child has turned 18. However, there's a three-year time limit for filing a motion in court to have a parent found in contempt for willfully failing to obey a child support order. Each month of overdue support can count as a separate contempt count, so the time limit can apply to the latest due date for unpaid or partially paid support. (Cal. Code Civ. Proc. § 1218.5 (2024).)

(Learn more about child support enforcement in California.)

When Are California Judges Likely to Order Retroactive Child Support?

When judges are issuing initial child support orders, it's up to them to decide whether to grant a request to make those orders retroactive. (Cal. Fam. Code § 4009 (2024).)

For instance, a judge may decide that retroactive child support is appropriate when there was a delay in the case, and the parent who owes support wasn't providing voluntary or temporary support for the child in the meantime.

How Far Back Can Retroactive Child Support Go?

As a general rule, California judges may make initial child support orders retroactive to the date when a parent (or child support agency) filed a "petition, complaint, or other initial pleading" (which could include a request for support in a divorce petition).

However, if the other parent wasn't served with the petition within 90 days after it was filed (and wasn't trying to avoid being served), the judge may not make the support order retroactive earlier than the date of service. (Cal. Fam. Code § 4009 (2024).)

How Is Retroactive Child Support Calculated?

When a judge orders retroactive child support, the amount will be calculated in the same way as for current support payments. Under California's child support guidelines, that calculation is largely based on both parents' incomes and the amount of time the children spend with each of them. If there's been a long delay in the case and the parents' financial circumstances and custody arrangements have changed during that time, the judge could take those changes into account when determining the amount of retroactive support.

Can Judges Order Retroactive Child Support Modifications?

Parents can request a modification of child support in California, but they'll generally have to prove there's been a significant change in circumstances that requires a different amount. Judges may decide to issue retroactive orders modifying support.

However, because of federal notice requirements, the modified support order may not go back earlier than when the other parent received notice of the request (by being served with the notice of motion or order to show cause.)

(Cal. Fam. Code § 3653(a); 42 U.S.C. § 666(a)(9) (2024).)

When Are Retroactive Child Support Modifications Mandatory?

Although it's usually up to individual judges to decide whether to make a child support order or modification retroactive, there are two situations when California law requires child support modifications to be retroactive. Unless there's a good reason otherwise, any orders to modify or terminate child support must be retroactive when a judge has ordered the change because:

• either parent has become unemployed, or
• a parent has experienced a change in income as a result of being called to active duty in the military and deployed out of state.

In these scenarios, the modified support order will be retroactive to the later of the following dates:

• the actual unemployment or activation date, or
• when the notice of motion, order to show cause, or activation notice was served.

(Cal. Fam. Code § 3653(b), (c) (2024).)

When Do Parents Have to Return Overpayments After a Retroactive Support Modification?

When a judge has issued a retroactive order lowering or terminating child support, the parent who was receiving support may be required to pay back the other parent for the difference between the amount received and what's due under the retroactive modification. The judge may order the repayment over time and in a way that's fair and reasonable, after considering the circumstances—including the amount of money involved and the financial impact on the support recipient. (Cal. Fam. Code § 3653(d) (2024).)

Getting Help With Retroactive Child Support

When you're getting divorced, you may request temporary child support while your divorce case is proceeding. Temporary support orders typically last until the divorce is finalized and they're replaced with permanent orders—so you probably won't need to request retroactive child support as part of your divorce. (Cal. Fam. Code §§ 3600, 3601 (2024).)

Outside of the divorce context, you may apply for child support through California's Child Support Services. The state also has a network of Family Law Facilitators who can provide information about the child support process, including how to apply for retroactive support.

Despite these resources, you may need a lawyer's help if you need retroactive child support or a retroactive support modification. This is especially true when you're seeking a change in your existing support payments, and you can't reach an agreement with your co-parent on a modification.