How the window opens
The 4-business-day initiation window begins the day after the 30-business-day open-negotiation period ends. The provider initiates Federal IDR through the CMS portal at nsa-idr.cms.gov. Patients do not file Federal IDR.
Certified IDR entity (IDRE) selection
Once initiated, the parties have a procedure to jointly select a certified IDRE. If they can't agree, CMS assigns one. The selected IDRE conducts baseball-style arbitration: each party submits a proposed payment amount with supporting documentation; the IDRE picks one. There is no compromise ruling.
What patients should know
The provider runs this clock; patients do not. But the patient's parallel actions matter:
- NSA complaint window: 90 calendar days from the date you knew or should have known of the violation. File with CMS at 1-800-985-3059.
- Plan appeal: ERISA self-funded plans have a 180-calendar-day internal appeal window (29 CFR §2560.503-1). If the appeal is denied, you may have external review rights.
- State DOI complaint: If your plan is state-regulated, the state DOI also accepts complaints. Filing windows vary by state.
Batching rules
Under 45 CFR §149.510(c), multiple items or services can be batched into a single IDR initiation if they meet specific batching criteria (same provider, same plan, similar service type, within the same 30-business-day period). Batching reduces administrative cost for providers and IDREs.
Related healthcare resources
Informational, not medical, legal, or insurance advice. Consult a healthcare-billing attorney or patient-advocate before acting on a No Surprises Act dispute. The free CMS NSA complaint pathway is 1-800-985-3059.