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, and the Publication Announcement Letter, which explain most aspects of the MUE program, see the CMS Medically Unlikely Edits webpage.

MUE Adjudication Indicator (MAI)

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

  • Indicator MAI 1: Indicates a value adjudicated by claims processing systems at the claim line level. 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.
    • Example - Same HCPCS code is provided and billed on multiple claim lines (overutilization), with different modifiers. One modifier may be GA, indicating a valid ABN was obtained.
  • Indicator MAI 2: Indicates an absolute date of service edit based on policy, such as anatomic considerations, definition of the code, or published CMS policy. CMS has not identified any instances in which a higher value is payable. For date of service MUEs, the claims processing system sums all UOS on all claim lines with the same HCPCS/CPT code and date of service.
    • Example - There are no valid reasons to receive payment for a greater value that displays in the MUE tool regardless of supporting documentation.
  • Indicator MAI 3: Indicates a value adjudicated by claims processing systems at the date of service level. If claim denials based on these edits are appealed, MACs may pay UOS in excess of the MUE value if there is adequate documentation of medical necessity of correctly reported units. For date of service MUEs, the claims processing system sums all UOS on all claim lines with the same HCPCS code and date of service. These are “per day edits based on clinical benchmarks.
    • Example - It is unlikely for a supplier to provide the same value or more that displays in the MUE tool on a correctly coded claim. A claim with this value or more will be denied as an excessive/unnecessary number of units of service in the typical delivery of such items to beneficiaries. Suppliers should be prepared with sufficient supporting documentation which identifies why the beneficiary needed the displayed value, or more, units of service on the same day, same side to appeal the claim.



Last Updated Fri, 23 Sep 2022 20:14:03 +0000