The base child support order is in place, payments are coming in, and then an orthodontist sends a bill for $2,400 or an ER visit generates a $600 copay that insurance won’t cover. Nothing in the order says what happens next. Does the other parent owe half? Two-thirds? Nothing at all?
California law answers that question directly. Uninsured medical costs for a child aren’t left to negotiation or goodwill after the fact. They fall under a mandatory category of additional child support governed by its own statutes, with its own reimbursement clock and its own allocation formula. That formula changed significantly on September 1, 2024, and most of what you’ll find elsewhere hasn’t caught up to it yet.
At Morales Law, P.C., Marcus Morales holds a Certified Family Law Specialist designation, a credential issued by the State Bar of California’s Board of Legal Specialization that requires demonstrated experience and testing in family law. Navigating the current rules around medical expense add-ons, including where most parents make documentation mistakes, is exactly the kind of issue we work through with clients every day.
What Counts as a Mandatory Medical Add-On
Family Code section 4062(a)(2) requires a court to order reasonable uninsured health care costs for a child as additional child support, separate from whatever base guideline amount has already been calculated. This isn’t optional or discretionary. If the costs are reasonable, the court must order them.
Costs that qualify include co-pays, deductibles, prescription charges, and out-of-pocket dental, vision, or orthodontic expenses tied to medically necessary treatment. If a child needs braces, a specialist visit, or mental health therapy and the insurance plan doesn’t fully cover it, the remaining amount is a candidate for a medical expense add-on. Health insurance premiums work differently. Rather than being treated as a separate reimbursable expense after the fact, premiums are factored directly into the guideline child support calculation itself.
How the 2024 Law Change Affects the Split
Before September 1, 2024, the default rule under Family Code section 4061 split add-on expenses equally (50/50) unless the court ordered otherwise. Senate Bill 343 rewrote that default. The split is now proportional to each parent’s adjusted net disposable income.
The mechanics matter. The paying parent’s net disposable income is reduced by the basic child support amount before the proportion is calculated. The receiving parent’s net disposable income isn’t increased by the support received. When spousal support is also in the picture, the paying parent’s income is decreased and the receiving parent’s income is increased by that amount before the medical add-on allocation is figured.
The result is that a parent who earns significantly more than the other may now owe a greater share of a qualifying medical bill than they would have under the old flat rule. Either parent can request a different apportionment from the court, but absent that request, the proportional-to-income default governs any add-on expense incurred on or after September 1, 2024.
Deadlines & Documentation for Reimbursement Requests
A parent who pays a qualifying uninsured medical cost must deliver an itemized statement to the other parent within a reasonable time, and no more than 90 days after the cost was incurred. That 90-day window is one of the changes that came with the 2024 statutory update; the prior deadline was 30 days. Missing it can affect your ability to recover the other parent’s share.
Once the itemized statement is delivered, California law creates a rebuttable presumption that amounts actually paid for a child’s uninsured health care needs are reasonable. If the other parent wants to challenge the expense, they have to show why the charge was unreasonable. The parent who paid doesn’t have to prove the amount was justified just to get the process started.
How reimbursement works depends on what’s already been paid:
- If you’ve already paid the full bill, you seek reimbursement of the other parent’s court-ordered proportional share directly from them.
- If the provider hasn’t been fully paid yet, the other parent may be directed to pay their share directly to the provider.
When the Other Parent Won’t Pay
If the other parent disputes the reimbursement request and refuses to pay, California law doesn’t allow them to simply withhold while the issue is pending. The disputing parent must pay the requested amount first, then seek relief from the court. Either parent can file a motion to enforce a child support add-on order, and the court has discretion to award filing costs and attorney’s fees against a party who acted without reasonable cause or in bad faith.
In Santa Barbara County, that motion is filed with the Santa Barbara County Superior Court’s family law division. Self-represented parents who need help applying the proportional allocation formula to their specific income figures can get free assistance through the Family Law Facilitator’s Anacapa Division office at 1100 Anacapa Street, 2nd Floor, Santa Barbara.
What This Means for Your Situation
Family Code sections 4061, 4062, and 4063 set clear formulas and firm deadlines: what qualifies, how the post-2024 proportional split is calculated, and how long you have to document and request reimbursement. The problem isn’t usually knowing a rule exists. It’s applying the proportional allocation correctly to both parents’ income figures, catching a dispute before the documentation deadline passes, and knowing what to do when the other side refuses to comply.
If you have questions about whether a child’s medical bill qualifies, how your income figures affect your share under the new formula, or how to enforce an add-on obligation the other parent is ignoring, we offer a consultation and can walk you through exactly where your situation stands. Reach us at (805) 422-7966.