MUE Lookup Tool


Medically Unlikely Edit (MUE)

The CMS developed Medically Unlikely Edits (MUEs) to reduce the paid claims error rate for Part B claims. An MUE for a HCPCS/CPT code is the maximum units of service that a provider would report under most circumstances for a single beneficiary on a single date of service. All HCPCS/CPT codes do not have an MUE.

Although CMS publishes most MUE values on its website, other MUE values are confidential and are for CMS and CMS Contractors' use only. The latter group of MUE values should not be released since CMS does not publish them.

Inquiries about a specific claim should be addressed to the claims processing contractor.

Inquiries about the rationale for an MUE value should be addressed to your claims processing contractor or a national healthcare organization whose members often perform the procedure.

If a national healthcare organization, provider, or other party wants to submit a request for reconsideration of an MUE value, such requests should be addressed to:

National Correct Coding Initiative
P.O. Box 368
Pittsboro, IN 46167


Fax: 317-571-1745

For MUE Frequently Asked Questions and Answers (FAQs), MUE files, the Publication Announcement Letter which explain most aspects of the MUE program, and more, see the CMS Medically Unlikely Edits webpage.

MUE Adjudication Indicator (MAI)

Describes the type of MUE (claim line or date of service).

  • MAI 1: Applied at line level (claim line) - Appropriate use of modifiers to report the same code on separate lines of a claim will enable the reporting of medically necessary units of service in excess of MUE
  • MAI 2: Absolute criteria (date of service) - CMS has not identified any instances in which a higher value is payable
  • MAI 3: Value unlikely to appear on correctly coded claim but could, in unusual circumstances, be payable (date of service) - Exceptions rare, supporting documentation required



Last Updated Tue, 15 Mar 2022 18:44:51 +0000