How far back can a Medicare RAC audit go?

Three years. A Recovery Audit Contractor may not review a claim more than three years past the date it was first paid, counted to the date of the ADR for a complex review or the review results letter for an automated review. For hospital patient status reviews, CMS limited the look-back to 6 months from the date of service when the hospital submitted the claim within 3 months of that date.

What Is a RAC Audit in Medicare?

RAC audit

Short answer

A RAC audit is a post-payment review of Medicare fee-for-service claims by a Recovery Audit Contractor, a CMS contractor that finds overpayments and underpayments, which the MAC then adjusts by recouping overpayments and paying underpayments.

Last reviewed October 30, 2026 by the Remitwright billing team. Editorial policy

Also written asRACRACsRAC auditsRecovery Audit ContractorRecovery Audit ContractorsRecovery AuditorRecovery Audit Program

Congress mandated the Recovery Audit program in the Tax Relief and Health Care Act of 2006 to find improper payments on Medicare fee-for-service claims: RACs identify the errors and MACs adjust the claims⁴. CMS uses four geographic RAC regions plus a nationwide Region 5 for DMEPOS and home health and hospice claims, with Performant in Regions 1 and 2 and Cotiviti GOV Services in Regions 3 through 5¹. A review is either automated, run against claim data at the system level, or complex, where a qualified reviewer reads the medical record¹.

RACs work only on review topics CMS approves, and they may not review a claim more than three years past its initial paid date, counted to the date of the ADR for a complex review or of the results letter for an automated one. They may not pick claims at random to request records; selection has to come from data analysis². The RAC is paid a contingency fee based on what is collected, and on an appealed claim the fee waits until the MAC and QIC levels are decided^2,3.

Every finding opens a 30-day discussion period. The RAC waits 30 calendar days from the review results letter before sending the claim to the MAC, and documents sent with a discussion request in that window are reviewed together with the original ADR response; once the claim has gone to the MAC, a discussion request is invalid². Discussion is optional and does not cost you the right to appeal³, which runs through a redetermination with the MAC once the adjustment is made. Use discussion when the RAC missed a record and the appeal when you dispute its reading of the rules.

Example

RAC audit in practice

A RAC's review results letter finds an overpayment on a group's claims for one service under an approved review topic. Within 30 days the practice sends a discussion request with operative notes the RAC had not seen, and the RAC reverses part of the finding before sending the rest to the MAC for adjustment. Hypothetical example.

RAC audit

RAC audit in practice

A RAC audit is part of medical billing audit, one of the services a dedicated biller runs for you.

Questions about a RAC audit