How to read the California IDR market
California accounts for 2.6% of national federal IDR dispute volume in the CMS public files. For a provider group, the useful comparison is rarely the national average. The better question is how a payer behaves in the same state, service mix, and specialty lane.
The tables below show the payer, code, and IDR entity mix that shape California disputes. Use them to spot where an underpaid out-of-network book may deserve a closer NSA workflow review.
Top payers in California federal IDR disputes
| Payer | Disputes | Provider win rate |
|---|---|---|
| Anthem Blue Cross | 37,146 | 88.1% |
| Aetna | 13,791 | 94.4% |
| BLUE SHIELD OF CA | 9,727 | 76.2% |
| UnitedHealthcare | 8,257 | 85.3% |
| Cigna | 6,741 | 81.1% |
| Cigna / MultiPlan | 3,702 | 81.2% |
| UMR (clearhs.com) | 1,881 | 86.4% |
| UMR (clearhealthcloud.com) | 1,150 | 87.2% |
| Cigna / Zelis | 591 | 80.5% |
| kp.org | 270 | 57.1% |
Top service codes in California
| Code | Service | Disputes | Provider win rate |
|---|---|---|---|
| 99284 | Emergency department visit for the evaluation and management of a patient, which requires | 19,478 | 87.8% |
| 99285 | Emergency department visit, high severity, requiring urgent evaluation | 17,978 | 88% |
| 85025 | Complete blood count (CBC) with automated differential | 7,639 | 85.6% |
| 36415 | Routine venipuncture (blood draw) | 6,691 | 88.9% |
| 99283 | Emergency department visit for the evaluation and management of a patient. Modifier 57 ind | 5,278 | 87.7% |
| 80048 | Basic metabolic panel (8 blood chemistry tests) | 4,316 | 85.5% |
| 93005 | Electrocardiogram (ECG) tracing only, without interpretation | 3,875 | 89% |
| 80053 | Comprehensive metabolic panel (14 blood chemistry tests) | 3,625 | 85.6% |
| 99291 | Critical care, first 30-74 minutes | 3,526 | 88.2% |
| 81001 | Urinalysis, automated, with microscopy | 3,144 | 85.1% |
Certified IDR entity mix
| Certified IDR entity | Disputes | Provider win rate | Median award |
|---|---|---|---|
| Maximus Federal Services, Inc. | 6,307 | 94.1% | 24.6x |
| Federal Hearings and Appeals Services, Inc. | 6,212 | 86.4% | 2.5x |
| Island Peer Review Organization | 4,456 | 99.2% | 4.9x |
| Provider Resources, Inc. | 4,332 | 93.6% | 14.9x |
| C2C Innovative Solutions, Inc. | 3,992 | 91.5% | 3.7x |
| MCMC Services, LLC | 3,058 | 95.3% | 4.2x |
| EdiPhy Advisors, L.L.C. | 3,019 | 97.4% | 4.5x |
| iMPROve Health | 2,493 | 84.1% | 3.9x |
Filing checklist before you take California claims to IDR
- Confirm the claim is NSA-eligible: emergency care, or out-of-network care at an in-network facility, with no state arbitration law that displaces the federal process for that plan type.
- Start open negotiation within 30 business days of the initial payment or denial notice. The negotiation window then runs 30 business days.
- If negotiation fails, initiate federal IDR through the portal within 4 business days after the window closes.
- Batch same-payer items in the same service code category. Open negotiation periods starting on or after November 1, 2026 can batch up to 50 line items per dispute, up from 25.
- Budget for fees: the federal administrative fee is $15 per party for disputes initiated on or after June 11, 2026 (down from $115), and the non-prevailing party pays the certified IDR entity fee.
- Anchor your offer to the data: the California median provider-won award is 4.5x QPA across 87,181 disputes.
The fee and batching changes come from the May 2026 federal IDR operations final rule. See the 2026 and 2027 No Surprises Act changes guide for the full timeline, or request a free NSA audit to see how your claims compare.
Open the live California dashboard
Filter California disputes by specialty, payer, and year to compare the public benchmark with your own out-of-network payment experience.
FAQ
How many federal IDR disputes are in California?
The California page currently shows 87,181 CMS disputes in the benchmark dataset.
What is the provider win rate in California?
The non-default provider win rate in California is 86.5% in this dataset.
Why can California differ from national IDR averages?
State, payer, service-code mix, and routing rules can change the economics of a dispute. That is why state-specific benchmarks are more useful than a national number.
How do I start a federal IDR case for a California claim?
Start open negotiation within 30 business days of the initial payment or denial. If it fails, initiate IDR through the federal portal within 4 business days. California providers should also confirm whether a state arbitration law controls the claim before filing.
Related benchmarks
Sources and method
Providers won 85.8% of 3.39 million federal IDR disputes through 2025Q4, with a median provider-won award of 4.7x the qualifying payment amount, per CMS public use files.
- CMS: Federal IDR reports and public use files
- CMS: Federal IDR operations final rule fact sheet
- CMS: Federal IDR timeline for claims
Data source: CMS Federal IDR public use files, coverage through 2025Q4; data build 2026-09-24. Counts are CMS dispute counts unless a table says line items. Win rates on this page exclude payer no-show defaults unless labeled otherwise. Award multiples are medians versus the qualifying payment amount (QPA). Dollar figures, where shown, come from CMS QPA-and-offer fields or are anchored estimates, not payment records. This page is informational, not legal or reimbursement advice.