The Centers for Medicare and Medicaid Services (CMS) developed Medically Unlikely Edits (MUEs) in 2007 to reduce the paid claims error rate for Part B claims. A MUE for a HCPCS/CPT code is the maximum number of units of service a physician should bill, under most circumstances, for one beneficiary on one date of service. Items billed above the number of units are considered "medically unlikely" and are automatically denied. All HCPCS/CPT codes do not have a MUE.

Currently, all CMS claims processing contractors adjudicate MUEs against each line of a claim rather than the entire claim. Thus, if a code is reported on more than one line of a claim by using CPT modifiers, each line with that code is separately adjudicated against the MUE.

Recent Government Accountability Office (GAO) and Office of Inspector General (OIG) studies uncovered vulnerabilities in the MUE program. They discovered that some physicians may be receiving excess payments because they are inappropriately reporting the same code on more than one line of a claim. As a result, as of April 1, 2013, CMS plans to convert the edit processing for some codes to date of service edits where possible.

Physicians should take steps to ensure they are appropriately coding bilateral services, and multiple units of service, utilizing appropriate modifiers when billing on separate claim lines.

Contact: Michele Kelly, (213) 226-0338 or mkelly@cmadocs.org.