No Surprises Act IDR disputes, by the numbers
When an insurer and a provider can't agree on an out-of-network bill, the No Surprises Act sends them to independent dispute resolution (IDR): binding arbitration where each side offers a price and the arbiter picks one. CMS publishes every dispute line item. Below: all 1,632,680 dispute line items from the federal IDR public use file, 2025 Q2 edition (cumulative since the process began in 2022).
What this means for a patient
Two facts matter if you got a surprise bill. First, the dispute is between the provider and the insurer, not you: once a qualifying service enters IDR, federal law bars the provider from billing you beyond in-network cost sharing while the dispute is open. Second, providers win overwhelmingly, which tells you insurer initial offers in these disputes are often below what an independent reviewer thinks is fair. If a provider is coming after you for the balance of a surprise emergency or facility bill, that bill likely qualifies for No Surprises Act protections and should not exist.
Most frequent insurers in IDR
| Insurer | Dispute items | Provider won |
|---|---|---|
| UnitedHealthcare (incl. UMR) | 388,273 | 87% |
| Aetna | 245,379 | 93% |
| Cigna | 101,686 | 78% |
| Blue Cross And Blue Shield Of Texas | 77,325 | 88% |
| Bcbstx | 57,442 | 96% |
| Cigna Healthcare | 52,365 | 95% |
| Bcbs Of Texas | 37,990 | 90% |
| Bluecross Blueshield Of Texas | 32,866 | 88% |
| Bcbs Of Tx | 30,346 | 89% |
| Aetna Health Plans | 23,323 | 82% |
| Anthem Blue Cross Blue Shield | 20,979 | 82% |
| Blue Cross Blue Shield Of Arizona | 15,837 | 87% |
| Blue Cross | 15,653 | 91% |
| Umr, Inc. | 14,742 | 97% |
| Florida Blue | 12,896 | 98% |
| Bcbs | 12,835 | 82% |
| Cigna Health And Life Insurance Company | 12,649 | 74% |
| Unitedhealthcare Uhc | 11,877 | 78% |
| Uhc | 11,481 | 69% |
| Blue Cross Blue Shield Of Texas | 10,658 | 97% |
Where the disputes are
| State | Dispute items |
|---|---|
| Texas | 718,984 |
| Arizona | 144,015 |
| Florida | 115,890 |
| Tennessee | 70,191 |
| New York | 49,660 |
| California | 48,955 |
| Georgia | 46,362 |
| New Jersey | 42,293 |
| Indiana | 42,151 |
| Oklahoma | 28,913 |
| Ohio | 25,637 |
| Arkansas | 25,514 |
| Nevada | 23,643 |
| Missouri | 20,186 |
| Louisiana | 18,761 |
Texas alone accounts for about 44% of all disputes: a high uninsured-adjacent share of facility billing plus aggressive ER and air-ambulance arbitration practice. Source: CMS Federal IDR Public Use File, 2025 Q2 (as of January 21, 2026).
Frequently asked
What is the No Surprises Act IDR process?
Independent dispute resolution is the binding arbitration process created by the No Surprises Act: when an out-of-network provider and a health plan cannot agree on payment for a qualifying service, each submits an offer and a certified independent arbiter picks one. CMS publishes the outcomes quarterly.
Who wins most IDR disputes?
In the CMS public use file through Q2 2025, decisions favored providers about 87% of the time versus about 13% for plans and insurers, with a small number of split decisions. The lopsided split is one of the most-studied findings in the program.
Can I be billed while my surprise bill is in dispute?
No. For services protected by the No Surprises Act, the provider may only bill you in-network cost sharing while the dispute is pending. If you are being balance-billed for a qualifying emergency or facility service, that billing violates the rule and you can appeal or complain to your state and CMS.
Does this apply to employer plans?
It applies to most group health plans and issuers for emergency services, air ambulance, and certain facility-based services from out-of-network providers. Disputes that do not qualify go to state law instead.