What Is a CPT Code, and How Do I Look One Up?

A Current Procedural Terminology (CPT) code is a five-character code that describes a medical service or procedure, like an office visit, a lab test, or a surgery. The American Medical Association maintains the CPT code set, and Medicare and other insurers use it to process claims. You can find these codes on your Medicare Summary Notice (MSN) and itemized bills, and you can look one up by searching the code with the words "medical billing code," which is the method the Centers for Medicare & Medicaid Services (CMS) suggests.

What does CPT stand for?

CPT stands for Current Procedural Terminology. The American Medical Association (AMA) describes it as a list of terms and five-digit codes that mainly describe medical services and procedures done by doctors and other health care professionals.

The AMA says CPT is designated under the Health Insurance Portability and Accountability Act (HIPAA) as a national coding set for physician and other health care professional services. That's why nearly every bill from a doctor's office, and many hospital bills, use CPT codes.

What's the difference between CPT and HCPCS codes?

CMS explains that the Healthcare Common Procedure Coding System (HCPCS) has two levels:

• Level I is CPT. These codes are five characters and are maintained by the AMA. Most are all numbers, like 99213. The AMA also has some alphanumeric categories.
• Level II codes are maintained by CMS. They start with a letter followed by 4 numbers, like E0143. CMS says they're used mainly for products, supplies, and services that CPT doesn't cover, such as ambulance services and medical equipment like walkers, wheelchairs, and oxygen supplies.

So if you see a code that starts with a letter on your Medicare notice, it's usually a Level II HCPCS code.

What types of CPT codes are there?

The AMA lists several categories:

• Category I: The main codes for procedures and services, numbered 00100 to 99499. Office visits, surgeries, X-rays, and lab tests fall here.
• Category II: Tracking codes used to measure quality of care.
• Category III: Temporary codes for new technology and procedures.
• Proprietary Laboratory Analyses (PLA) codes: Codes for specific lab tests.

Most codes you'll see on a bill are Category I.

Where do I find CPT codes on my bills?

On your Medicare Summary Notice (MSN). On the claims pages, each service has a short description followed by the code in parentheses. Medicare's sample Part B MSN shows "Eye and medical examination for diagnosis and treatment, established patient, 1 or more visits (92014)." The number in parentheses is the code.

On an itemized bill. Look for a column labeled "CPT," "HCPCS," "procedure code," or just "code." Hospital bills may also show "revenue codes," which group charges by department (pharmacy, lab, room). If you only see revenue codes, ask for the CPT or HCPCS codes too.

On a Medicare Advantage Explanation of Benefits. Many plans list a code next to each service.

If your bill doesn't show codes at all, call the billing office and ask for an itemized bill with codes.

How do I look up a CPT code?

Here are a few ways, starting with the simplest.

1. Search it online. CMS's guide for consumers suggests typing the code number with the term "medical billing code" into a search engine and reading the descriptions. Compare what you find with the care you got.

2. Check your MSN description. Medicare already prints a plain-language description next to each code. If the bill and MSN describe the same code differently, ask the provider why.

3. Use Medicare's Procedure Price Lookup. Medicare.gov has a Procedure Price Lookup tool for outpatient procedures. You can search by procedure name or code to compare national average costs for some procedures done in a hospital outpatient department and in an ambulatory surgical center.

4. Use CMS's Physician Fee Schedule search. CMS has an online search for the Physician Fee Schedule that shows payment information by code. It's built for providers, so it's more technical, but it's free.

5. Ask the billing office. You can always say: "Can you tell me what code [number] is for, in plain English?"

What should I check once I know what a code means?

Compare the description with what happened at your visit:

• Does the service match? If the code describes a procedure you didn't have, ask about it.
• Does the level match? As a general guide, office visit codes come in levels based on how complex the visit was. If a short, simple check-in was billed at a high level, you can ask the office to explain how they chose the code.
• Does the count match? If the code appears more than once, ask whether it's a duplicate or a legitimate repeat.
• Does it match your records? CMS suggests asking for your medical records and comparing them to the bill.

If the code still doesn't make sense, ask the provider to review it. If they agree it's wrong, they can send a corrected claim to Medicare or your plan.

What should I say if I think a code is wrong?

You might say:

"Hi, I'm calling about my visit on [date]. My bill shows code [number], which I looked up as [description]. That doesn't match what happened at my visit, which was [what you remember]. Can someone review the coding and let me know if it should be corrected?"

Keep the conversation factual. Coding is detailed work, and an honest question is the best way to get a second look.

Frequently asked questions

Are CPT codes the same everywhere?

Yes. The AMA describes CPT as a uniform coding language used by doctors, health systems, and insurers across the United States.

Why does my bill have a code that starts with a letter?

Codes that start with a letter followed by four numbers are usually HCPCS Level II codes, which CMS maintains for things like equipment, supplies, and ambulance services.

Do I need to buy a coding book to look up codes?

No. A simple web search of the code with "medical billing code," as CMS suggests, is usually enough for a consumer.

Can a wrong code change what I pay?

Yes. The code tells Medicare or your plan what was done, and that affects what's approved and what you owe.

Want plain-English explanations of the codes on your bills?

Bill Review Coach is a monthly medical bill review service for seniors and their families. Snap a photo of your bill or Medicare notice, and we'll translate the codes into plain English, flag any that don't seem to fit, and tell you what to ask on the phone. You make the calls and write the emails; we help you know what to say.