CPT Code

Definition

A CPT code (Current Procedural Terminology) is a five-character numeric code that identifies a specific medical service or procedure performed by a healthcare provider. CPT codes are maintained by the American Medical Association (AMA) and are required on every outpatient medical claim. The CPT code determines the base reimbursement amount — each code maps to a specific dollar value on the payer's fee schedule.

Why CPT Codes Matter

The CPT code is the single most important field on a medical claim for determining payment. A higher-level E/M code (99215 vs 99213) can mean a $100+ difference in reimbursement for the same patient visit. Incorrect CPT coding — upcoding, undercoding, or using obsolete codes — triggers denials, audits, and compliance risk. AMA updates the CPT code set annually on January 1.

How CPT Codes Work

CPT codes are organized into three categories. Category I (most common): six sections covering E/M, anesthesia, surgery, radiology, pathology, and medicine. Category II: supplemental tracking codes (performance measures). Category III: temporary codes for emerging technology. Each claim line pairs a CPT code with an ICD-10 diagnosis code and any applicable modifiers. The payer processes the claim based on this code combination.

Related Terms

ICD-10 code — diagnosis codes paired with CPT codes. CPT modifier — additional detail appended to CPT codes. Fee schedule — the reimbursement rate per CPT code. Bundling — when multiple CPT codes are combined into one.

Common Questions

Who sets CPT code reimbursement rates?

The AMA defines the codes. CMS sets Medicare reimbursement rates through the Medicare Physician Fee Schedule (MPFS), updated annually. Commercial payers set their own rates, typically as a percentage of Medicare rates (e.g., 120% of Medicare). Each payer's fee schedule is different.

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This glossary is for informational purposes. Consult official billing guidelines and payer policies for definitive definitions. Last updated: 2026-04-06.