Effective April 1, 2009, the Centers for Medicare and Medicaid Services (CMS) has temporarily uspended the 98 laboratory/pathology CPT codes in the Phase VIII “Medically Unlikely Edits MUES).” The Phase VIII MUEs became effective on January 1, 2009.

CMS developed the MUEs to reduce errors in claims paid under Medicare Part B. MUEs are the maximum units of service (UOS) edits assigned to each CPT/HCPCs code and are applied to each code reported for the same beneficiary on the same date of service.