Revised Modification to the Medically Unlikely Edit (MUE) Program

CMS implemented Medically Unlikely Edits (MUE) on January 1, 2007, to reduce the claims error rate. At the onset of the MUE Program, the MUE value for a HCPCS code was only adjudicated against the units of service (UOS) reported on each line of a claim. On April 1, 2013, CMS modified the MUE program so that some MUE values would be date of service edits rather than claim line edits. At that time, CMS introduced a new data field to the MUE edit table termed “MUE adjudication indicator” or “MAI”. CMS is currently assigning a MAI to each HCPCS code. CR8853 contains current and updated background information for these modifications.

• MUEs for HCPCS codes with a MAI of “1” will continue to be adjudicated as a claim line edit.
• MUEs for HCPCS codes with a MAI of “2” are absolute date of service edit. These are “per day edits based on policy.
• MUEs for HCPCS codes with a MAI of “3” are date of service edits. These are “per day edits based on clinical benchmarks”.

A denial of services due to an MUE is a coding denial, not a medical necessity denial. The presence of an Advance Beneficiary Notice (ABN) shall not shift liability to the beneficiary for UOS denied based on an MUE. ABN issuance based on an MUE is NOT appropriate.