Answers / Timeline
The IDR arbitration timeline, deadline by deadline
Median decision: 37 days. But the clocks start much earlier. IDR arbitration under the No Surprises Act runs on a chain of business day deadlines that begins the day the payer pays or denies the claim: 30 business days to send the open negotiation notice, 30 business days of negotiation, 4 business days to file for arbitration, offers due within 10 business days of arbitrator selection, a decision due 30 business days after selection, and payment due 30 calendar days after the decision. Miss any provider-side deadline and the claim is usually gone for good.
Every clock in order
| Step | Deadline | Starts when |
|---|---|---|
| Send open negotiation notice | 30 business days | You receive the payer's initial payment or notice of denial |
| Open negotiation period | 30 business days | The negotiation notice is sent |
| Initiate IDR arbitration | 4 business days | The negotiation period ends |
| Submit offer and evidence | 10 business days | The certified IDR entity is selected |
| Arbitrator's decision | 30 business days | The certified IDR entity is selected |
| Payer pays the award | 30 calendar days | The decision is issued |
Deadlines set by the No Surprises Act and its implementing rules. The 37 day median decision time is computed from the CMS federal IDR public use files, 2023 through 2025.
What each window is really for
The negotiation notice is a formality you cannot skip. You cannot file for arbitration without having opened negotiation first, so the 30 business day notice window is the real statute of limitations on the claim. Groups that batch remits monthly and sort them by payer rarely miss it. Groups that work underpayments ad hoc miss it constantly.
Negotiation is 30 business days of mostly silence. Some payers settle here, and a settlement that reaches the right number is a fine outcome. But the window's main function is procedural: when it closes, the path to arbitration opens.
The 4 business day filing window kills the most claims. It is short, it starts on a date you have to track yourself, and nothing reminds you. This single deadline is the strongest argument for running IDR arbitration as a pipeline with dates on every claim rather than as a drawer of exceptions.
Offers are one shot. Within 10 business days of the arbitrator being selected, each side submits one payment offer with its evidence. There is no hearing and no rebuttal round, so the offer number and the packet behind it decide the case. What wins is covered in who wins IDR arbitration.
Is it too late for older claims?
Often not. The 30 business day clock starts only when the payer delivers a compliant initial payment or notice of denial to the provider. Remits that never reached you, payments the plan sent to the patient instead, and notices missing the information the rules require may never have started the clock at all. Before writing off a stack of older underpayments, it is worth checking what the payer actually sent and when.
What happens when the payer misses its deadlines
The two payer-side deadlines that matter: submitting its offer within 10 business days of selection, and paying the award within 30 calendar days of the decision. A payer that never submits an offer generally loses by default, since the arbitrator must pick one of the offers in front of them. A payer that does not pay a binding award is rarer; the award does not expire, and the recourse is a CMS complaint backed by the documented decision, then your attorney.
The arbitrator's own 30 business day decision deadline slips in practice without consequence to the parties. The published record still shows a median of 37 days from initiation to decision, which makes IDR arbitration one of the fastest paths to resolving an underpaid out-of-network claim.
Tracking these deadlines in a spreadsheet?
Bring your payer mix and rough out-of-network volume to a 30 minute call. We will show you which claims are still inside their windows and what a flat fee arrangement looks like. Talk to an IDR specialist.