CPT Structure and Categories
Learn how procedure codes are organized, what the three CPT categories are for, and how to navigate the code set to find the right one.
By the end of this lesson you can
- Describe the structure of CPT and its three categories
- Navigate the CPT sections and use the index correctly
- Explain what the CPT symbols and conventions signal
- Distinguish CPT from HCPCS Level II and know when each applies
Lesson Notes
Read through the key concepts before you try the challenge.
Codes for what was done
You code an office visit at Lakeside Medical Associates.
The ICD-10-CM code says the patient has osteoarthritis of the left knee. That explains why care was needed. It says nothing about what the provider actually did — the examination, the joint injection, the X-ray. Without procedure codes, the claim describes a problem and requests payment for nothing in particular.
Your task: Learn the code set that describes services delivered, and how it is organized.
CPT stands for Current Procedural Terminology. It is maintained by the American Medical Association, revised annually with changes effective 1 January, and it describes the services and procedures a provider performs. Every CPT code is five characters.
| Category | Format | Purpose | Optional? |
|---|---|---|---|
| Category I | Five digits, e.g. 99213 | Procedures and services in widespread use — the great majority of coding | No — these drive payment |
| Category II | Four digits plus F, e.g. 3006F | Performance measurement and quality reporting | Yes, but often required by quality programs |
| Category III | Four digits plus T, e.g. 0510T | Emerging technology, services, and procedures | No — use instead of an unlisted Category I code when one exists |
| Section | Range | Covers |
|---|---|---|
| Evaluation and Management | 99202-99499 | Office visits, consultations, hospital care |
| Anesthesia | 00100-01999 | Anesthesia services |
| Surgery | 10004-69990 | Surgical procedures by body system — the largest section |
| Radiology | 70010-79999 | Imaging and radiation oncology |
| Pathology and Laboratory | 80047-89398 | Lab tests and pathology |
| Medicine | 90281-99607 | Immunizations, cardiovascular studies, therapies |
Key terms
- HCPCS Level II
- A separate code set — one letter plus four digits — for supplies, durable medical equipment, drugs, prosthetics, and ambulance services. Maintained by CMS.
- Unlisted procedure code
- A code used when no specific code describes the service. Requires a written report and is always manually reviewed, so it slows payment.
- Bundled service
- A service considered part of another and not separately payable. Reporting it separately is unbundling.
- Global period
- A window after a procedure during which related follow-up care is included in the original payment.
CPT covers physician services and procedures. HCPCS Level II covers what CPT does not — the wheelchair, the injectable drug, the surgical dressing, the ambulance transport. A single encounter can require both: a CPT code for administering an injection and a HCPCS Level II code for the drug that was injected.
A provider administers a therapeutic injection. Which code or codes are needed?
Challenge
Apply what you've learned in this lesson.
You will need access to a current CPT code set. Your program or library should provide one; the AMA publishes it annually.
- Locate the six Category I sections in the code book and note the page each begins on. Read the guidelines at the start of the Surgery section.
- Look up a routine office visit in the index, then find the code in the main text. List every piece of information the main text gives you that the index did not.
- Find one Category III code and explain in two sentences why it exists rather than a Category I code.
- For a patient receiving an injectable medication, identify what you would need from the documentation to code both the administration and the drug.
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