CPT is a standardized set of codes used to report medical, surgical, and diagnostic procedures and services to various entities, including physicians, insurance companies, and accreditation organizations. Medical bills are billed electronically using CPT codes combined with ICD-9-CM or ICD-10-CM numerical diagnostic codes.

The CPT codes are used to submit claims to federal and private payers when rendering healthcare. As CPT codes provide a detailed description of a procedure or service, they eliminate subjective interpretations of what was delivered to the patient.

The American Medical Association (AMA) developed CPT® codes in 1966 to standardize reporting of medical, surgical, and diagnostic services and procedures provided in hospital and outpatient settings.

The evolution of healthcare – including the availability of new services and the retirement of outdated procedures – is a significant consideration. Every year, the AMA releases new, revised, and deleted CPT® codes and changes to coding guidelines. The AMA also releases more minor updates to various sections of the CPT® code set.

Moreover, the AMA updates CPT® terminology or medical language to reflect advances in medicine. Though the AMA owns the copyright to CPT®, it invites participants to contribute to the ongoing maintenance of the code set and welcomes feedback on the codes and code descriptors.

Understanding CPT® codes

CPT® codes are composed of five characters. In general, codes are numeric, but some codes include a fifth character, such as A, F, T, or U. These are some examples:

92526      Oral function therapy

0638T      Ct breast w/3d bi c-/c+ 

CPT® Code Types: A Quick Guide

Providers assign codes to every service or procedure they perform. It even includes codes for services and procedures not specifically named in another CPT® code, called unlisted codes.

The AMA has organized CPT® codes logically by classifying them into three types based on the wide range of services and procedures they cover:

CPT® Category I: Codes commonly used by providers to report their services and procedures comprise the largest body of codes

CPT® Category II: Additional tracking codes used in performance management

CPT® Category III: Emerging and experimental codes for reporting services and procedures

CPT® Category I:

Most CPT® codes are in Category I. There are a variety of existing services and procedures that are widely used and, where appropriate, approved by the Food and Drug Administration (FDA).

In general, Category I codes, which are typically represented by five characters, are arranged numerically. Codes are resequenced in one discrepancy from the expected order. In order to facilitate quick access to related codes – and help coders select the best codes – the AMA groups similar codes together. Resequenced codes occur when a new code is added to a family of codes, but there is no sequential number assigned to it.

Another exception to numerical code order involves evaluation and management codes (E/M codes). Although E/M codes begin with 9, they are printed first in CPT® code books, as you can see below in the code outline for Category I. E/M services are among the most frequently reported healthcare services, so the AMA chose this order. As with resequenced codes, this arrangement is intended for coding efficiency.

Codes for CPT® Category I fall into six main categories:

Evaluation & Management (99202–99499)

Anesthesia (00100–01999)

Surgery (10021–69990) The code range is further divided into smaller groups by body area or system

Radiology Procedures (70010–79999)

Pathology and Laboratory Procedures (80047–89398)

Medicine Services and Procedures (90281–99607)

CPT® Category II:

Four numbers and the letter F make up Category II codes, which providers can assign in addition to Category I codes. There is no reimbursement associated with Category II codes, unlike Category I codes.

The CPT® code book typically places Category II codes after Category I codes. These codes are listed as follows:

Composite Measures (0001F–0015F)

Patient Management (0500F–0584F)

Patient History (1000F–1505F)

Physical Examination (2000F–2060F)

Diagnostic/Screening Processes or Results (3006F–3776F)

Therapeutic, Preventive, or Other Interventions (4000F–4563F)

Follow-up or Other Outcomes (5005F–5250F)

Patient Safety (6005F–6150F)

Structural Measures (7010F–7025F)

Nonmeasure Code Listing (9001F–9007F)

CPT® Category III:

Category III codes, characterized by four numbers and a letter T, usually follow Category II codes in the code book. Category III codes are temporary codes used to identify new technologies, services, and procedures.

In Category III, temporary codes describing new services and procedures can remain for up to five years. They must meet Category I criteria, including FDA approval, evidence that the procedure is widely practiced, and evidence that it has proven effective. A new Category I code will be assigned to them. Providers can also eliminate Category III codes if they do not use them.

The AMA releases new or updated Category III codes semiannually via its website but publishes the deletions of Category III codes with the full list of temporary codes annually.