California workers' comp

Independent Bill Review (IBR) in California workers' comp: deadline, fee and win rate

If a second bill review doesn't fix an underpayment, Independent Bill Review (IBR) sends the dispute to an outside reviewer under contract with the state. Providers win nine times in ten. Almost nobody files.

Providers win almost every time

The Division of Workers' Compensation publishes IBR results. They're lopsided:

Set that against the volume. One billing vendor's clients filed more than 225,000 second reviews in 2023 (DaisyBill, vendor-reported). Fewer than 5,000 disputes a year go on to IBR, so nearly everything that survives second review is dropped, even though the next step usually succeeds.

What IBR can and can't decide

IBR decides one thing: how much a bill should be paid under the fee schedule, or under a contract that's agreed to apply. That covers fee schedule amounts, coding and modifier rules, and bundling. Under 8 CCR 9792.5.7(b), everything else must be settled first, including:

• Liability. Whether the injury or the treatment is covered. The 30 days don't start until that's resolved in your favor (LC 4603.6(a)).
• Whether a contract applies. If the dispute is whether a PPO rate should have been used at all, IBR won't decide it. Use the written demand under LC 4609(c)(2), which makes the payor prove its right to the discount within 30 business days.
• Services with no fee schedule, and the choice of an analogous code, unless the schedule allows analogous coding.

Medical necessity disputes go through utilization review and Independent Medical Review (LC 4610.5), not IBR.

One date, one code, unless you consolidate

By default, each IBR request covers one provider, one patient, one claims administrator, and one date of service with one billing code (9792.5.7(a)). At $335 a request, that adds up fast. 8 CCR 9792.5.12 lets you combine up to 20 disputes into one request for one fee when they share common issues:

• Several codes, one visit. Multiple billing codes for one patient on one date of service, with no dollar limit.
• One code, several visits. Multiple dates of service for one patient and one billing code, up to $4,000 in dispute.
• One code, many patients. If Maximus allows it after consulting DWC, multiple patients, one claims administrator and one billing code, where the requests show "a possible pattern and practice of underpayment", up to $4,000 in total or under $50 each.

That last option is how a practice fights a carrier's systematic underpayment of a single code across its whole caseload, for a single fee. If a request doesn't qualify, Maximus can split it, and each piece costs another $335.

How to file

1. Start the clock from the second review determination. You have 30 calendar days from its service, or five days after the postmark if it was mailed without proof of service (9792.5.7(c)).
2. File online or on DWC Form IBR-1 and pay the $335 fee.
3. Assemble the record, indexed by category (9792.5.7(d)(2)): the original bill; anything furnished with it; any applicable contract provisions; the first EOR; your second review request; anything sent with it; and the second review determination.
4. Serve the claims administrator with a copy of the request and the documents at the same time. Documents that came from the claims administrator can be described instead of copied (9792.5.7(f)).
5. Send the documents to the reviewer within 10 days of the notice of assignment (LC 4603.6(b)).
6. Calendar the decision and the refund. If you win, the carrier pays the amount found due and reimburses the fee.

A worked example

A Sacramento orthopedic office billed an established-patient visit with modifier 25 (99214-25) and a knee injection on April 14, 2026. The carrier paid the injection and bundled the visit: $0.00, CARC 97. The second review, citing the separate documentation and the NCCI rules California adopts, came back unchanged.

The office files one IBR request: one patient, one date of service, one code, $226.57 in dispute (the OMFS maximum for the visit), and a $335 fee. If the reviewer agrees, the carrier owes $226.57 plus the $335 fee back. Had the carrier also cut the injection, both codes from that one visit could have gone in the same request for the same single fee.

OMFS maximums are base maximum fees under 8 CCR 9789.12.2 for an office (place of service 11) in the Sacramento locality, from the CMS RVU26B file and the $51.6091 conversion factor adopted in 8 CCR 9789.19(m) (DWC OMFS), computed by Redress's fee schedule engine. The visit, bill and carrier responses are illustrative.

Expect the state to be slow

The statute sets deadlines for the state as well. DaisyBill reports that the DWC assigned only 4% of 2025 IBR applications within the statutory deadline (DaisyBill, vendor-reported). Plan for recoveries to arrive months after filing, and track every application until the award and the fee refund are paid.

If you disagree with the decision

The decision is final and binding unless a party files a verified appeal with the Workers' Compensation Appeals Board within 20 days of service. It's presumed correct, and set aside only on clear and convincing evidence of one of five grounds: the administrative director exceeded its powers, fraud, a reviewer's material conflict of interest, bias, or a plainly erroneous finding of fact that's a matter of ordinary knowledge (LC 4603.6(f)).

Redress files IBR on the second reviews that still come back wrong, and consolidates them where the rules allow. A licensed biller signs each application. You pay a share of what's recovered, nothing up front. See the full appeal path, from EOR to award.

Last reviewed October 14, 2026. This guide is general information about California workers' compensation billing rules, not legal advice. Check the current statute and regulation before filing.