The CPT code set (copyright protected by the AMA) describes medical, surgical, and diagnostic services and is intended to provide physicians, coders, patients, accreditation organizations, and payers with uniform information about medical services and procedures for administrative, financial, and analytical purposes. The CPT codes are used by all types of health care providers to bill for their services. The CPT codes are divided into five categories based on the type of service provided: basic clinical services; special clinical techniques; procedures; organ/systemic functions; and specialized diagnostic tests. These can be thought of as headings under which all medical services can be classified. Each category has its own set of codes that can be used to describe a particular service or procedure. For example, a physician might use the basic clinical services code to report results from a complete physical examination while another doctor might use the same visit to report treatment for depression. Both examples would be described using different codes but both would be considered medical visits for purposes of insurance reimbursement. CPT codes are published in a monthly journal called Medical Claims Processing. They also have a web site where you can search by diagnosis or procedure to find what codes have been used by other doctors. You can even look up specific codes used by other doctors so you know what they mean when they submit a claim for payment. Coding guidelines are also available there to help you determine whether it's appropriate to use a particular code on a given claim.