The NCCI edits were created by the Centers for Medicare and Medicaid Services (CMS) in order to reduce improper coding. NCCI consists of two different types of edits: (1) procedure-to-procedure (PTP) edits, known as “NCCI edits;” and (2) units-of-service (UOS) edits, known as Medically Unlikely Edits (MUE).

The PTP edits (NCCI edits) define pairs of HCPCS (Healthcare Common Procedure Coding System) and CPT codes that are in “conflict” and should not be reported together. If two codes in conflict are billed together, payment for one of the two codes might be inappropriate.

In some cases, the conflict may be overcome to permit payment by applying a proper modifier to the billed code(s), such as modifier 59. The UOS edits (MUE) define codes that contain a maximum allowable number of units of service by the same provider, for the same patient, on the same date of service, and on the same claim line. There are six different categories of NCCI edits:

  1. PTP edits for practitioner and ASC services.
  2. PTP edits for outpatient hospital services.
  3. PTP edits for DME.
  4. MUEs for practitioner and ASC services.
  5. MUEs for outpatient hospital services.
  6. MUEs for DME.

The NCCI Edits can be accessed here.