CPT stands for Current Procedural Terminology. It is a five digit number-series owned by the American Medical Association. It is used to identify medical services and procedures, and diagnostic procedures. This is how physicians communicate with third-party insurers.
ICD stand for International Statistical Classification of Diseases and Related Health problems. It assigns a number figure for each disease including any circumstance leading to bodily harm. It is published by the World Health Organization.
They are dependent upon each other because when physicians request for payment (from insurance companies), they identify the services they have performed by CPT code and they consequently have to attach the ICD codes to support the claims.
