Category III Codes: The Hidden Factor In Your Revenue Strategy

December 18, 2025
By: Laura Manser, CPC, CPCO, CDEO, CEMC, CPMA, CIRCC, RCC, Director of Provider Education

In the latest RBMA Bulletin, Laura Manser breaks down why Category III CPT codes are more than temporary placeholders—they’re a critical bridge between emerging technology and future reimbursement.

Radiology is advancing at a pace that even seasoned administrators sometimes struggle to track. Artificial intelligence tools are moving from vendor demos into daily workflow. Interventional procedures are expanding beyond traditional definitions. Quantitative imaging is rewriting the way radiologists approach diagnosis. Yet in the middle of this rapid change, one element is often overlooked: Category III CPT codes.

These codes are easy to dismiss. They do not have Relative Value Units (RVUs) assigned. Reimbursement is inconsistent. They are temporary by design. But ignoring them is a costly mistake. As a professional coder and compliance officer, I have seen first-hand how misunderstanding Category III codes leaves practices under-reporting services, losing opportunities to influence payer policy, and missing the chance to shape the future of radiology reimbursement.

What Category III CPT Codes Really Are

Think of Category III codes as the AMA’s way of saying, “This is new, and we need to keep track of it.” They’re temporary, four-digit codes that always end in “T.” They cover emerging technologies that aren’t widespread enough yet to qualify for a permanent Category I code.

Per the CPT manual instructions: “If a Category III code is available, this code must be reported instead of a Category I unlisted code. This is an activity that is critically important in the evaluation of health care delivery and the formation of public and private policy. The use of these codes allows physicians, insurers, health services researchers, and health policy experts to identify emerging technology, services, procedures, and service paradigms for clinical efficacy, utilization and outcomes.” – (AMA CPT Manual, Category III Codes)

THE KEY TAKEAWAY: Category III codes are not optional when available. Reporting them is what creates the data trail that determines whether a service becomes permanent and how it is reimbursed in the future.

Why Category III CPT Codes Exist

Category I CPT codes take time. To get one, a service must be performed nationally, backed by strong clinical evidence, and often evaluated by the RUC for RVUs. That’s a long runway. Category III codes shorten the distance between innovation and recognition. They don’t guarantee coverage, but they give us a structured way to show payers and policymakers that a service is real, being performed, and deserves attention.

In radiology, this matters a lot right now. Just look at the new 2025 codes 0877T-0880T for augmentative analysis of chest CT imaging data with AI technology, used to find diagnostic subtype classifications of interstitial lung disease. The data can guide physicians in selecting appropriate treatment for individual patients and may help avoid unnecessary procedures such as lung biopsy. Without Category III, this type of innovation would still be buried under “unlisted” and completely invisible in national data.

The Reimbursement Reality

Here’s the part everyone cares about: money. Category III codes don’t have RVUs, so payment is totally up to the payer. While reimbursement is tough, it is also an opportunity for practices that approach these codes strategically to set themselves apart. And yes, the denial rates are high if you just drop them on a claim and hope for the best.

But here’s what I’ve seen work:

• Document the “why.” Don’t just say the AI tool was used. Spell out how it changed the diagnosis or management.
• Get prior auth when you can. Some payers will approve if you ask ahead of time.
• Appeal. A lot of these denials get overturned when you push back with documentation.
• Track your data. Denial reasons, appeal outcomes, even which payers are more open to these codes, all that information becomes leverage.

The Lifecycle of Category III Codes

Category III codes don’t live forever. Typically, they stick around for up to five years. During that time, data gets collected, and then the code either graduates to Category I or gets retired.

That’s why it’s risky not to report them. If nobody uses the code, there’s no data. And no data makes it a lot easier for a code to disappear instead of becoming permanent.

Why This Should Matter to You

Let’s be real: if your practice isn’t reporting Category III codes, you’re not just missing out on potential reimbursement. You’re also cutting yourself out of the process that shapes how these services get recognized down the road.

Here’s what’s at stake:

• Influence. Using these codes adds your practice’s experience to the national picture.
• Compliance. Using an unlisted code when a Category III exists isn’t correct coding.
• Opportunity. Some payers will pay for these codes. If you never bill them, you’ll never know.

Practical Moves

1. Train your radiologists and coders so everyone knows when a Category III code applies.
2. Build documentation templates that highlight why the service was necessary and what it added. 
3. Keep payer conversations active. Don’t wait for denials, ask questions up front.
4. Set up a simple tracking system. Creating a basic spreadsheet with columns for: Code, Date of Service, Payer, Initial Response (Paid/Denied/Pending), Appeal Filed (Y/N), Outcome, and Notes. Track denial reasons word-for-word, you’ll start seeing patterns. Maybe Blue Cross always denies 0042T but approves it on appeal with additional documentation, while Anthem pays it outright. That intelligence becomes gold when you’re training staff or negotiating contracts. Update it monthly and review quarterly. After six months, you’ll have real data to show payers about utilization and outcomes, which beats anecdotal conversations every time.
5. Monitor AMA code releases every January and July, so you’re not blindsided by new additions

Bottom Line

Category III codes aren’t a hassle. They’re a tool. They give us a way to capture innovative technology, show its value, and set ourselves up for better reimbursement in the future.

If you treat them like a dead end, you miss the chance to be part of the decision-making process. If you treat them like a bridge, you position your practice to be ahead of the curve.

So next time you see a code ending in “T,” don’t ignore it. That little letter could shape the way radiology gets paid in the years to come.

The full article is also available here.