What is the Medicare National Correct Coding Initiative (NCCI)? The Medicare National Correct Coding Initiative (NCCI) promotes national correct coding methodologies and controls improper coding leading to inappropriate payment. The coding policies are based on coding conventions defined in the American Medical Association’s (AMA’s) Current Procedural Terminology (CPT) Manual, national and local Medicare policies and edits, coding guidelines developed by national societies, standard medical and surgical practice, and/or current coding practice.