Methodology
Where the numbers come from, and what they can and cannot tell you.
How does the IDR calculator work? Every number on this site is computed from the CMS federal IDR public use files, the official record of arbitration under the No Surprises Act. The calculator multiplies the qualifying payment amount you enter by your specialty's median award multiple, defined as the median award as a multiple of the qualifying payment amount across decided line items in that specialty. The national headline figures are computed separately, at the dispute level: providers win 85.8 percent of federal IDR disputes that reach a decision, the median award is 4.7 times the qualifying payment amount, and the median time from filing to decision is 37 days, based on 3.39 million disputes in the federal public use files.
Data source
CMS publishes the outcome of every federal independent dispute resolution (IDR) case in quarterly public use files. The files cover 2023 through 2025 and include 3.39 million disputes: the service codes in dispute, the parties' offers, the qualifying payment amount, which party prevailed, the award, and the dates of filing and decision. No patient information appears in the files or on this site.
Two grains, kept separate
The files can be read at two levels, and mixing them produces wrong numbers, so we never do.
- Dispute grain. One row per arbitration case. The national headline stats on this site are dispute grain: the 85.8 percent provider win rate, the 4.7 times median award, and the 37 day median time to decision.
- Line-item grain. One row per service code inside a dispute. A single dispute can contain many line items. All specialty figures on this site are line-item based where dollars are involved: each specialty's median award multiple is the median award as a multiple of the qualifying payment amount across decided line items in that specialty, and the per-code tables on the specialty pages are line-item grain too.
This is why the specialty multiples do not average out to the national 4.7 figure. They are answering different questions at different grains.
What "decided" means
Win rates and award multiples are computed in decided disputes only. Decided means a certified IDR entity reviewed both offers and picked one. Default decisions, where one party never submitted an offer or never paid its fee, are excluded. Defaults inflate win rates without saying anything about the merits, so they are left out of every figure on this site.
The estimate formula
The calculator does one multiplication: estimated award = your qualifying payment amount times your specialty's median award multiple. Multiples are rounded to one decimal before multiplying, dollar results to the nearest dollar, win rates to one decimal, and days to whole numbers. The fee comparison defines recovery as the estimated award minus the payer's initial payment, because that is the base contingency filers charge 15 to 25 percent of. It also notes the $15 federal administrative fee each party pays per dispute, for disputes initiated on or after June 11, 2026.
Update cadence
The site is refreshed each time CMS releases a new federal IDR public use file, normally quarterly. Each refresh recomputes every specialty figure and regenerates every page from the new file.
Limitations
- Medians hide spread. Half of decided line items resolve above the specialty median and half below. High-dollar surgical codes behave very differently from low-dollar ancillary codes inside the same specialty.
- The estimate is not case-specific. Awards vary with the billing code, the payer, the state, batching, and the quality of the written submission. The public use files do not capture submission quality.
- Specialty buckets are ours. CMS does not publish a clean specialty field, so line items are grouped into 22 buckets by service code. Codes that span specialties sit in the closest bucket.
- Federal process only. States with their own surprise billing arbitration (for example New York and Texas for some claim types) route some disputes outside the federal files entirely.
- Eligibility is not modeled. The calculator assumes the claim qualifies for federal IDR under the No Surprises Act. Office procedures, Medicare, Medicaid, and self-pay patients do not qualify.
Use the numbers
Run your own inputs through the IDR calculator, or read your specialty's page from the specialty table. To browse every published dispute, payer, and IDR entity, see idrexplorer.com. If you want a specialist to file for you for a flat fee per arbitration, see lidoidr.com.