Question: What is the difference between Medically Unlikely Edits and Mutually Exclusive Edits under the National Correct Coding Initiative? They sound the same to me. Codify Subscriber Answer: Although the terms may sound alike, CMS has established Medically Unlikely Edits (MUEs) as a claims-editing parameter distinct from mutually-exclusive edits under the Correct Coding Initiative (CCI). In fact, CMS has abandoned the distinction between mutually exclusive edits and comprehensive/component edits in favor of combining those edits under the umbrella of Procedure-to-Procedure (PTP) edits, also referred to as Column 1/Column 2 edits. Purpose: The PTP edits identify different procedure codes that you should not bill together. CMS describes these as “automated prepayment edits that prevent improper payment when certain codes are submitted together.” On the other hand, the MUE edits define the maximum units of service that you can bill for a single CPT® or HCPCS code for the same patient on the same date of service. For instance, 44970 (Laparoscopy, surgical, appendectomy) has an MUE of 1, because it would be impossible to remove more than one appendix from one specific patient. For the PTP edits, CCI provides the following modifier indicators that tell you when or if you can override a given edit pair: You can find more in-depth clarification on these indicators at www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/Downloads/How-To-Use-NCCI-Tools.pdf.