Who's winning IDR arbitration?
Under the No Surprises Act, out-of-network payment fights go to arbitration and the outcome becomes public record. That record answers a question nobody announces: who files the most disputes, who actually wins them, and how the market splits across payers and states — quarter by quarter.
What “market share” means here
Not a survey, not a guess — a count. Because IDR outcomes are public, market share is something you can read off the record directly.
A firm's share of the No Surprises Act is how much of the fight it accounts for: the disputes it files, the disputes it wins, and the states where it leads. NSA Tracker counts all three from the public, fair-use record and plays them on one timeline.
Four ways to read the share
Share of disputes filed
Which firms and representatives file the most out-of-network line items — the raw volume of the fight, by filer, market, and quarter.
Share of disputes won
Volume is not victory. Provider win rate — read directly from the record — separates who shows up from who actually prevails.
By payer & benchmark
Every insurer anchors arbitration to its own QPA. We publish where each payer's benchmark sits against its local market, as an exact index.
By state
Market share is local. The firm that owns one state may be absent in the next — the map shows who leads each one, quarter by quarter.
The market changes hands
Leadership in this record is not stable. The firm leading the most states early on was overtaken more than once, and the largest filer by volume shifted with it — none of it announced anywhere. Play it in order and it's simply what the record says. See it live in who files and who wins, on the map as who owns each state, or profile any firm, payer, or code through the representatives view. For the dollars side of the same record, see out-of-network revenue.
Common questions
What is No Surprises Act market share?
It is the share of out-of-network payment disputes — filed or won — that a given firm, representative, or payer accounts for under the No Surprises Act. Because the arbitration outcomes are public record, that share can be counted rather than estimated: who brings the most disputes, who prevails most often, and how that splits across states and quarters.
What is IDR market share?
IDR market share is the same measure scoped to federal Independent Dispute Resolution — the arbitration channel the Act created. It captures who is active in IDR and who wins there, by service code, state, and payer, read from the public record of dispute outcomes.
Who has the largest IDR market share?
It changes hands. Early in the record one firm led the most states; over the following quarters it was overtaken more than once, and the biggest filer by volume was not always the same name. Because leadership shifts quarter to quarter, the honest answer is the live one — NSA Tracker plays the record in order so you can see who leads now and who is rising.
How is No Surprises Act market share measured?
By counting the public record along a few lenses: share of disputed line items filed, provider win rate, position of each payer's QPA benchmark against its local market, and who leads each state. NSA Tracker counts these directly — where a figure is a modelled estimate rather than a count, it is labeled as such.
Which insurer sets the lowest benchmark?
Every payer sets its Qualifying Payment Amount differently, and the gap is measurable. NSA Tracker publishes each payer's benchmark position as an exact index against the local market — not as a dollar headline, which the public record cannot support. Explore the benchmarks view to compare payers directly.