Dental billing in California: payment deadlines, interest and overpayment rules

The short answer: since January 1, 2026, a dental plan in California has 30 calendar days to pay, contest or deny a complete claim. A plan that pays late owes interest of 15 percent a year, automatically. A payer that wants money back must ask in writing within 365 days of paying, and the dentist then has 30 working days to refund or contest. These rules cover state-regulated plans and insurers, not self-funded employer plans.

I practice in Glendora, in the San Gabriel Valley. Until this year the payment deadline was counted in working days, and a follow-up calendar built on the old count is now wrong. This page sets out the rules as they stand, with the code sections, so your office can check its own claims against them.

This is general information from a practicing dentist, not legal advice. Statutes are amended; confirm the current text before you rely on it in a dispute.

The rules at a glance

Which rules apply to which plan

• Dental plans licensed by the Department of Managed Health Care (DMHC). The Health and Safety Code applies, and section 1371 names specialized plans, which is what a dental plan is. Many of the largest dental plans in the state hold a DMHC license.
• Dental insurers regulated by the California Department of Insurance (CDI). The Insurance Code applies, with the same 30-calendar-day deadline and a 10 percent interest rate.
• Self-funded employer plans. These are governed by federal ERISA law and are generally outside state prompt-payment rules, even when a familiar insurer administers them. The patient's card or the plan documents will say whether a plan is self-funded.
• Medi-Cal Dental. The state program has its own billing rules, set out in its provider handbook.

What changed on January 1, 2026

Assembly Bill 3275 replaced working days with calendar days. A plan used to have 30 working days to pay a complete claim, and a health maintenance organization had 45. Now every plan and insurer has 30 calendar days from the day it receives the claim. The same 30 calendar days is the limit for telling the dentist, in writing, that a claim is contested or denied.

Expect to see the old figures for a while. Reference copies of the Knox-Keene Act printed before 2026, and summaries built on them, still say 30 or 45 working days. For a claim received on or after January 1, 2026, the current text of section 1371 is the one that counts, and it says calendar days for specialized plans such as dental plans too.

Two details matter at the front desk. The clock starts on a complete claim, so a missing radiograph or narrative gives the plan a reason to contest and restart it. And the interest is automatic: the plan is meant to add it to a late payment without being asked.

When a payer asks for money back

1. Check the date. The request must be sent within 365 days of the date the claim was paid, unless the payer says the overpayment came from fraud or misrepresentation.
2. Check the notice. It has to be in writing and identify the claim, the patient and the date of service, with a clear explanation of why the payer believes it overpaid.
3. Answer within 30 working days. Either refund it or contest it in writing, naming the portion you dispute and your reasons.
4. Watch your next deposits. Payers often recover an overpayment by reducing a later payment. That is the takeback that makes a deposit fail to match its EOBs.

What a California office should track

• The date each claim was received, not only the date it was sent. Your clearinghouse report shows it.
• Day 30. A complete claim with no payment and no written contest by then is late.
• Interest on late payments. Compare the payment date with the receipt date on anything that arrives after the deadline.
• The payment date on every claim, because that is what the 365-day overpayment limit runs from.
• Every deposit against its remittances. It is the only way to see a takeback when it happens. The guide to ERA, EOB and EFT explains how the three records tie together.

If a state-regulated plan is not following these rules, a provider can file a complaint with DMHC for a licensed plan or with CDI for an insurer. The California Dental Association also helps members with payer disputes.

Dental billing help for California offices

Tracking those dates takes the same repetitive attention as posting itself. Sai for Dentists is an AI agent, built by Amalgamate Technologies and Simular, that works on a dedicated computer in your office. It retrieves EOBs from your payer portals, posts payments and write-offs in your practice management software and matches every insurance deposit to the statements behind it, so a late payment or a takeback is visible the day it lands.

The startup cohort is enrolling dental offices in Los Angeles County, Orange County, Riverside County, San Bernardino County, San Diego County and Ventura County. Cohort offices use Sai free as design partners, then move to fixed startup pricing. See how the Southern California cohort works, or compare the cost with an outsourced billing company.

Sources

• California Health and Safety Code sections 1371 and 1371.1, as amended by Assembly Bill 3275 (2024), operative January 1, 2026.
• California Insurance Code sections 10123.13 and 10133.66.
• California Code of Regulations, title 28, section 1300.71.
• Department of Managed Health Care, All Plan Letter 25-007, AB 3275 guidance.
• 45 CFR 162.925 and CMS guidance on EFT and virtual credit cards.
• Medi-Cal Dental Provider Handbook.