Because MUEs are based on current coding guidelines as well as current clinical practice, they are only applicable for the time period in which they are in effect. A change made to an MUE value for a particular code is not retroactive; however, in exceptional circumstances when a retroactive effective date is applied, MACs are not directed to examine prior claims but only “claims that are brought to their attention.”2
It also is important to realize that not all
MUEs are publicly available and many are confidential. When claim denials occur, particularly in the context of multiple units of a particular code,
automated MUE edits should be among the issues that are suspected. Physicians may resubmit RTP claims on separate lines if a claim line edit
(MAI of 1) is operative. An MAI of 2 suggests a coding error that needs to be corrected, as these coding approaches are generally impossible based on definitional issues or anatomy. If an MUE with an
MAI of 3 is the reason for denial, an appeal is possible, provided there is documentation to show that the service was actually provided and that it was medically necessary.
Dermatologists should be vigilant for unexpected payment denials, which may coincide with the implementation of new MUE values. When such denials occur and MUE values are publicly available, dermatologists should consider filing an appeal if the relevant MUEs were associated with an MAI of
1 or 3. Overall, dermatologists should be aware that many MUEs that were formerly claim line edits
(MAI of 1) have been recently transitioned to date of service edits (MAI of 3), which are more restrictive.