HCPCS Level I vs Level II — What Coders Need to Know
May 27, 2026
The Healthcare Common Procedure Coding System (HCPCS) is built in two layers. Confusing them is one of the most common mistakes new coders make. Here's a precise breakdown of what each layer covers, who owns it, and when to use which.
Level I — CPT codes
Level I of HCPCS is the Current Procedural Terminology (CPT) code set published and maintained by the American Medical Association (AMA). CPT codes are five-digit numeric codes (with occasional alphanumeric "CPT II" performance measurement codes and "CPT III" emerging technology codes).
Examples:
- 99213 — Established patient office visit, level 3
- 27447 — Total knee arthroplasty
- 93000 — Electrocardiogram, complete
- 87635 — SARS-CoV-2 detection by amplified probe
CPT covers virtually all physician services: evaluation and management (E/M), surgery, anesthesia, radiology, pathology, and medicine procedures. If a service is performed by a physician or qualified health professional, the code that describes the work is almost always a CPT code.
CPT is copyrighted by the AMA. Practices and software vendors that use CPT codes must license them from the AMA. This is why HCPCSLookup.com — and most free Internet HCPCS references — only cover Level II.
Level II — alphanumeric HCPCS codes
Level II of HCPCS is administered by the Centers for Medicare & Medicaid Services (CMS). Codes are five characters: a leading letter (A–V) followed by four digits.
Examples:
- J0129 — Injection, abatacept, 10 mg
- E0601 — Continuous positive airway pressure (CPAP) device
- A0425 — Ground mileage, per statute mile
- G0438 — Annual wellness visit, initial
Level II covers categories of items and services that CPT does not, or that CMS needs to bill separately:
- Drugs administered other than orally (J-codes)
- Durable medical equipment, prosthetics, orthotics, and supplies (E, K, L codes)
- Ambulance and transportation services (A-codes)
- Hospital outpatient temporary codes (C-codes)
- Dental procedures (D-codes — administered by the ADA)
- Medicare temporary codes for procedures and professional services (G-codes)
- Non-Medicare codes for commercial payers (S-codes)
- State Medicaid codes (T-codes)
- Vision, hearing, and speech-language pathology supplies (V-codes)
Because Level II is administered by CMS for the federal Medicare and Medicaid programs, the code set, descriptors, and updates are in the public domain. Anyone can search, publish, and integrate Level II codes without a license.
When to use which
For a single patient encounter, you may end up billing both a Level I code and one or more Level II codes:
Example: A patient receives an abatacept (Orencia) infusion in a physician office.
- 96365 (CPT, Level I) — Intravenous infusion, initial up to 1 hour. Describes the infusion service.
- J0129 × N (HCPCS, Level II) — The abatacept drug itself, billed in 10 mg units.
The CPT code captures the professional and facility work of delivering the infusion. The J-code captures the drug. Both bill on the same claim.
Why we only cover Level II
HCPCSLookup.com is a free, comprehensive reference. Publishing CPT (Level I) codes would require either licensing the codes from the AMA (which prohibits redistribution to non-licensees) or operating under a strict, AMA-controlled framework. We chose to focus on the CMS-administered Level II set so the entire reference can be free, complete, and unrestricted.
If you need Level I (CPT) codes, the AMA publishes the CPT codebook annually and licenses the codes for software integration. Many practices also access CPT through their EHR vendor's AMA license.
Quick reference
| Aspect | Level I (CPT) | Level II |
|---|---|---|
| Maintained by | AMA | CMS |
| Format | 5-digit numeric (mostly) | Letter + 4 digits |
| Coverage | Physician services, surgery, E/M, lab, radiology | Drugs, DME, supplies, transportation, temporary codes |
| Copyright | AMA — license required | Public domain (CMS) |
| On HCPCSLookup? | No (license restriction) | Yes — all ~8,600 codes |
The takeaway: if your code is a five-digit number, it's CPT (Level I), and you'll need the AMA codebook or your EHR. If your code starts with a letter, it's HCPCS Level II, and you can look it up here.