Independent Bill Review (IBR) is California work-comp's neutral, binding process for resolving disputes over the amount owed under a fee schedule. Established under LC §4603.6 and administered by Maximus Federal Services on behalf of the DWC, IBR exists for exactly one situation: you and the payer agree the bill is payable, but disagree on how much the fee schedule requires.
Where IBR sits in the dispute ladder
IBR is never your first move. The path is fixed:
- Payer issues an EOR that underpays.
- You file a Second Review (SBR-1) within 90 days.
- Payer issues a final EOR on the Second Review. If they still underpay or deny…
- You file for IBR within 30 days of that final determination.
Skip the Second Review and IBR will reject your application — the Second Review is a mandatory prerequisite. File late and you lose the right to IBR entirely.
The mechanics
- Deadline: 30 days from the final Second Review EOR.
- Filing fee: $180, paid up front. If Maximus rules in your favor — even partially — the payer reimburses the fee, so a winning IBR costs you nothing.
- The application: the DWC IBR-1 form, identifying the billed amount, the allowed/paid amount, the disputed difference, and the grounds.
- The decision: Maximus issues a written determination that is binding on both parties, subject only to narrow appeal.
The fee is recoverable — so winnable disputes are essentially free to pursue. If your Second Review rebuttal was sound (e.g., a §9789.30(d) PPO reduction), the same argument carries into IBR, and Maximus determinations on identical issues become precedent you can cite.
What IBR can — and cannot — decide
IBR decides amount disputes under the fee schedule, and nothing else. It is the right tool when the fight is "the MLFS says $X, you paid $Y." It is the wrong tool when the dispute is about something other than the dollar amount:
- Liability disputes — the employer/claims administrator disputes responsibility for the claim itself → that's a lien under
LC §4903.05, not IBR. - Coverage / threshold questions — whether an expense is even a covered §9793(h) medical-legal expense, or a §4060–4062 legal issue → that's a Petition for Determination to the WCAB under
CCR §10451.1.
Choosing the wrong forum wastes the filing window and the fee. The discipline is simple: amount dispute → IBR; liability dispute → lien; everything-else med-legal dispute → Petition for Determination.
Why teams under-use IBR
Many billing shops stop at the Second Review because tracking the 30-day IBR window across hundreds of bills is tedious, and the $180 feels like a gamble. It isn't — on a meritorious dispute the fee comes back, and a single recovered med-legal underpayment usually dwarfs it. The real cost is letting the window lapse. Treat IBR as the natural second step on every denied Second Review with a real fee-schedule argument behind it.
This guide is general information for California workers'-comp and med-legal billers, not legal advice. Statutes, fee schedules, and forms change — confirm against the current DWC regulations for your dates of service.