CPT Code 97598: Wound Debridement Billing and Coding Explained

A wound debridement claim may look straightforward at first. The provider performs the procedure, the documentation is completed, and the claim is submitted. Then a denial comes back because the wound was larger than 20 square centimeters, and the additional debridement area wasn't coded correctly.

This is where CPT code 97598 becomes important. It is the add-on code used with CPT 97597 when selective debridement extends beyond the first 20 square centimeters. While the rule sounds simple, mistakes in wound measurements, unit calculations, and documentation are common and can lead to delayed payments.

What Is CPT Code 97598

CPT code 97598 is used for selective wound debridement when the treated wound area is more than the first 20 square centimeters.

In simple words, it is an add-on code.

That means CPT 97598 cannot stand alone. It must be billed along with CPT code 97597.

CPT 97597 covers the first 20 square centimeters of selective debridement. CPT 97598 is added when the provider treats an additional wound area beyond the first 20 square centimeters.

For example, if the provider treats a wound area of 25 square centimeters, the first 20 square centimeters are billed with CPT 97597. The remaining 5 square centimeters are billed with one unit of CPT 97598.

CPT 97598 is only one part of wound care coding. If you're looking for a complete breakdown of the most commonly used wound care billing codes, read our Wound Care CPT Codes guide.

How CPT 97598 Works with CPT 97597

CPT 97598 is an add-on code, which means it cannot be billed by itself. It is reported alongside CPT 97597 when selective debridement extends beyond the first 20 square centimeters of treated wound area.

Here’s the basic structure: CPT 97597 covers the first 20 sq cm or less. CPT 97598 covers each additional 20 sq cm or part of it. 

For example, if a wound measures 35 sq cm after calculation, you would bill:

• CPT 97597 for the first 20 sq cm

• One unit of CPT 97598 for the remaining 15 sq cm

If a wound measures 42 sq cm, you would bill:

• CPT 97597 for the first 20 sq cm

• One unit of CPT 97598 for the next 20 sq cm

• A second unit of CPT 97598 for the remaining 2 sq cm

This is where many billing mistakes occur. Some teams forget that CPT 97598 applies even when the additional area is less than a full 20 sq cm. Others bill extra units without documentation to support the wound measurements. Both errors can lead to denials, payment delays, or lost revenue.

How to Calculate Units for CPT 97598 Correctly

Calculating units for CPT 97598 is simple once you understand the rule. The code covers each additional 20 square centimeters, or part thereof, beyond the first 20 square centimeters billed with CPT 97597.

Follow these steps:

1. Calculate the total wound surface area selectively debrided.

2. Bill CPT 97597 for the first 20 sq cm.

3. Subtract 20 sq cm from the total treated area.

4. Divide the remaining area by 20.

5. Round up to the next whole number to determine the number of CPT 97598 units.

Example

Total wound area debrided: 55 sq cm

• First 20 sq cm = CPT 97597

• Remaining area = 35 sq cm

• 35 ÷ 20 = 1.75

• Round up to 2

Bill: CPT 97597 × 1 and CPT 97598 × 2

If multiple wounds are selectively debrided during the same visit, calculate the total treated surface area before determining the number of CPT 97598 units. Accurate measurements and clear documentation are essential to support reimbursement and avoid denials.

What Documentation Do You Need to Bill 97598

Documentation is where wound care billing cases are won or lost. Payers scrutinize selective debridement claims closely, and missing any of the following can trigger a denial or a post-payment audit.

Your clinical notes should include:

• Wound size: Measured in square centimeters, documented before and after the session when possible

• Wound location: Specific anatomical location for each wound treated

• Type of debridement: The exact method used (e.g., sharp debridement with scalpel)

• Tissue removed: Description of necrotic or devitalized tissue present and removed

• Wound assessment: Condition of the wound bed, surrounding tissue, exudate, and any signs of infection

• Medical necessity: Why was debridement clinically necessary at this visit

• Provider credentials: Debridement must be performed by a licensed clinician within their scope of practice

Want to reduce denials even further? Our detailed Wound Care Documentation guide explains the documentation standards, common mistakes, and best practices that support clean claims.

FAQ

1.    What is the difference between 97597 and 97598?

CPT 97597 covers the first 20 square centimeters of selective wound debridement. CPT 97598 is an add-on code used for each additional 20 square centimeters, or part thereof, treated during the same session. 

2.    How many units of 97598 can be billed?

The number of CPT 97598 units depends on the total wound area debrided beyond the initial 20 square centimeters. One unit is billed for each additional 20 square centimeters, or part thereof.

3. Can CPT 97598 be billed alone?

CPT 97598 is an add-on code it cannot be billed on its own. CPT 97597 must be reported first for the initial 20 sq cm of debridement, and CPT 97598 is then used to capture any additional treated area.