Medically Unlikely Edits (MUEs) are edits that providers should become familiar with and understand their implications. Initially called “Medically Unbelievable Edits,” these edits were established in 2007 by CMS to reduce the paid claims error rate for Medicare Part B claims. An MUE for a HCPCS code is the maximum number of units of service that a provider may report under most circumstances for the same beneficiary, HCPCS code, date of service, and billing provider.
MUEs were designed to reduce errors due to clerical entries and incorrect coding based on anatomic considerations, HCPCS code descriptors, CPT coding instructions, established CMS policies, nature of a service/procedure, nature of an analyte, nature of equipment, and unlikely clinical treatment. Here are some examples:
- Code 44970, Laparoscopy, surgical appendectomy, has an MUE value of “1” since anatomically, there is only one appendix
- Code 22222, Osteotomy of spine, including discectomy, anterior approach, single vertebral segment; thoracic has an MUE value of “1” since the code descriptor refers to a single segment, and CPT coding instructions are that each additional vertebral segment is listed separately with code 22226, each additional vertebral segment.
Prior to implementation, all edits were reviewed by national healthcare organizations, and their alternative recommendations were taken into consideration. In 2008, CMS refined the edits based on 100% submitted claims data from a six month period in 2006.
Since October 1, 2008, the majority of existing MUEs have been published on this website: http://www.cms.hhs.gov/National-CorrectCodInitEd/08_MUE.asp#TopOfPage
The published MUEs consist of most of the codes with MUE values of 1-3. CMS will generally not publish all MUE values that are 4 or higher because of CMS concerns about fraud and abuse. In addition, a minimal number of MUEs with lower values that are believed by CMS to be particularly vulnerable to fraud and abuse may not be published. Although most HCPCS codes will have MUEs, some groups of codes have been temporarily excluded for future consideration.
The MUE values on the CMS website are updated on a quarterly basis coincident with each quarterly version of MUE. It is important to note that MUE values are not utilization guidelines. MUE values do NOT represent units of service that may be reported without concern about medical review. Providers should continue to only report services that are medically reasonable and necessary. Please refer to the CMS website for information on how Medicare adjudicates claims with MUEs.
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, the procedure described in the MUE Frequently Asked Questions (FAQ) should be followed. Such requests should be addressed to:
National Correct Coding Initiative
Correct Coding Solutions, LLC
P.O. Box 907
Carmel, IN 46082-0907
The request should include the rationale and any supporting documentation. CMS recommends, however that the party contact the national healthcare organization whose members perform the procedure prior to writing to Correct Coding Solutions, LLC. The national healthcare organization may be able to clarify the reporting of the code in question. In addition, if the national healthcare organization agrees that the MUE value should be modified, its support and assistance may be helpful in requesting the modification of an MUE value.
These tips will help you make sense of MUEs:
- Verify whether the service is coded with the correct code and the correct unit(s) of service
- Become familiar with MUEs that CMS has published. Note that there are two separate files available, one is for the practitioner/ durable medical equipment supplier, and the other one is for hospital outpatient services
- Verify whether your facility provided the number of units in question.
- Follow CMS’ guidance on separate line items and modifiers to report medically reasonable and necessary units of service in excess of an MUE value.