CPT code 97598 – Selective debridement, each additional 20 cm²

Key takeaways

CPT 97598 is an add-on code for selective debridement of each additional 20 cm², or part of it, beyond the first 20 cm².

It can’t be billed without CPT 97597 as the primary code. Standalone 97598 claims are rejected under standard add-on code edits, and payers apply their own edits.

Overcounting 20 cm² units without documented wound measurements brings audit and recoupment risk, and potential False Claims Act exposure for knowingly overbilled units.

Technique and depth decide the code. Selective debridement bills 97597/97598, non-selective methods bill 97602, and excision into subcutaneous tissue or deeper bills the 1104x series.

Pabau, the practice management platform we build, captures wound care CPT codes and submits claims through its Claim.MD clearinghouse integration.

CPT code 97598: Official descriptor and add-on code status

CPT code 97598 is the add-on code for selective debridement of each additional 20 cm² of open wound surface, or part of it. It applies whenever the total area debrided in a session exceeds the first 20 cm² covered by the primary code, CPT 97597.

The American Medical Association, which maintains the CPT code set, marks 97598 with a plus sign (+97598) to show its add-on status.

The official AMA descriptor for 97598 is a single long sentence. Here it is verbatim, broken at its own punctuation.

• Debridement (eg, high pressure waterjet with/without suction, sharp selective debridement with scissors, scalpel and forceps), open wound,
• (eg, fibrin, devitalized epidermis and/or dermis, exudate, debris, biofilm),
• including topical application(s), wound assessment, use of a whirlpool, when performed and instruction(s) for ongoing care,
• per session, total wound(s) surface area;
• each additional 20 sq cm, or part thereof (List separately in addition to code for primary procedure)

Two points matter for correct billing. The phrase “or part thereof” means any wound area above a 20 cm² threshold triggers one more unit, even if only 2 cm² remain. The closing instruction requires a primary procedure code, which is always 97597.

CPT 97597 vs 97598: The primary and add-on code pair

CPT 97597 and CPT 97598 work as a billing pair. CPT 97597 covers the first 20 cm² or less of selective debridement in a session. CPT 97598 adds one unit for every additional 20 cm², or part of one, beyond that threshold. 97597 can be billed alone, but 97598 can’t, because it only stacks on top of the primary code.

Both codes describe selective debridement, which removes devitalized tissue from the epidermis and dermis only. The AMA names high-pressure waterjet, irrigation, and sharp selective debridement with scissors, scalpel and forceps as the techniques. Non-selective methods, such as enzymatic agents and wet-to-moist dressings, bill under CPT 97602 instead.

How to calculate units: The 20 cm² rule for CPT code 97598

Unit calculation for CPT 97598 follows a straightforward formula, but errors here are a frequent audit trigger in wound care billing. The steps are:

1. Measure the total debrided wound surface area in cm².
2. Subtract 20 cm² (the area covered by one unit of CPT 97597).
3. Divide the remaining area by 20.
4. Round up any fraction to the next whole number (the “or part thereof” rule).
5. The result is the number of CPT 97598 units to bill.

The ladder below shows where each new unit starts, so you can read the count straight off the measured area.

Worked examples:

Every 97598 unit billed must be supported by a documented wound measurement in the medical record. Billing four units without a wound area of at least 81 cm² recorded in the progress note is an overcoding violation. Document the measurement before submitting the claim, not after.

CPT 97598 vs CPT 11042, 11043, and 11044: Choosing the right debridement code

The 97597/97598 pair and the 11042 to 11044 series both describe wound debridement, but they apply to different depths of tissue. Choosing the wrong series is a common miscoding error in wound care billing.

The key decision point is tissue depth and technique, not wound size or the instrument in the clinician’s hand.

• Excisional debridement of subcutaneous tissue or deeper uses the 1104x series, chosen by the deepest layer removed.
• Selective debridement of devitalized epidermis and/or dermis uses 97597/97598, whether by waterjet or by scissors, scalpel and forceps.
• Non-selective debridement, such as enzymatic agents or wet-to-moist dressings, uses 97602.

Billing the 1104x codes for a selective procedure is upcoding, and billing 97597/97598 for an excisional one is downcoding. Both create audit and compliance exposure.

Medicare and payer coverage for CPT code 97598

Medicare covers CPT 97598 under Local Coverage Determinations issued by each Medicare Administrative Contractor (MAC). Many MACs reference LCD L33821 (or its successor), which specifies qualifying wound types, visit frequency, and documentation requirements. Because LCD numbers and coverage criteria vary by MAC jurisdiction, verify your specific contractor’s current LCD before billing.

Qualifying wound types commonly covered under Medicare LCDs include:

• Diabetic foot ulcers
• Venous stasis ulcers
• Pressure injuries (stages II through IV)
• Post-surgical wounds with dehiscence or infection
• Arterial insufficiency ulcers
• Traumatic wounds requiring ongoing debridement

Commercial payers generally follow Medicare criteria but may impose additional prior authorization requirements or lower frequency limits. Always check the payer-specific policy before the first visit and document medical necessity explicitly in each progress note. Claims that lack a wound-type diagnosis consistent with the payer’s LCD are among the highest-volume denial reasons for 97598.

2025 Medicare reimbursement rates for CPT code 97598

Medicare pays for CPT 97598 at a lower rate than the primary code 97597 because it covers an incremental area, not a full session. Rates below are national averages from the 2025 Medicare Physician Fee Schedule and vary by geography through Geographic Practice Cost Index (GPCI) adjustments.

Use the CMS Physician Fee Schedule lookup tool for your locality’s current payment amount.

These are approximate national averages. Your payment varies by locality, practice setting, and whether the provider participates in Medicare. For RVU breakdowns and locality adjustments, the FastRVU lookup tool provides current Work, Practice Expense, and Malpractice RVU values for 97598. It also shows the GPCI multipliers for your geographic area.

Documentation requirements for CPT 97598

Every unit of CPT 97598 billed must be supported by a corresponding entry in the medical record. Missing or vague documentation is a leading reason claims pass initial submission but fail on post-payment audit. Each visit note must contain all of the following:

• Wound dimensions: Length x width (or length x width x depth) recorded in cm, with the total surface area calculated and documented.
• Tissue type debrided: Specify fibrin, slough, devitalized tissue, exudate, or biofilm, and confirm the debridement stayed within the epidermis and/or dermis.
• Technique used: Name the selective method, such as waterjet, irrigation, or scissors, scalpel and forceps, to support 97598 over 97602 or the 1104x codes.
• Medical necessity statement: A brief clinical rationale explaining why debridement was required at this visit and why the wound has not progressed to closure.
• Provider credentials: Document the name and credentials of the provider who performed the debridement.
• Date and time of service: Required for all wound care encounters, particularly in SNF and hospital outpatient settings.

Good medical billing compliance in wound care starts with a progress note written to answer an auditor’s likely questions. Without a recorded measurement, no unit count can be defended, however large the wound was.

Common billing errors and denial reasons for CPT 97598

Claim denials for CPT 97598 cluster around a small number of predictable errors. Most are preventable with a pre-submission checklist, and each returns a reason code, so knowing the common denial codes speeds up the fix.

• Billing 97598 without 97597: NCCI edits enforce the pairing at the claim level. A claim submitting 97598 alone is rejected under standard add-on code edits, and payers apply their own edits too. Always include 97597 as the primary code on the same claim.
• Unit miscalculation: This is a frequent overcoding error. A 35 cm² wound generates one unit of 97598, not two. Use the round-up rule carefully and record the wound area before calculating units.
• Missing wound measurements: Auditors compare billed units to documented area. If the note says “large wound” without a cm² figure, every 97598 unit on that claim is vulnerable to recoupment.
• Wrong code series: This means billing 97598 for excisional debridement into subcutaneous tissue or deeper. That work belongs to the 1104x series, which is chosen by the deepest layer removed.
• Exceeded frequency limits: Medicare LCDs specify the number of debridement visits covered per wound per period. Claims beyond those limits require documented failure of conservative treatment or a clinical exception letter.
• Missing diagnosis code: Every claim must pair 97598 with an ICD-10-CM code that supports medical necessity for debridement. A mismatch between the diagnosis and the wound type specified in the LCD causes non-covered-service denials.

For practices with recurring wound care denials, tracking denial reason codes per CPT code exposes systematic errors faster than reviewing claims one by one. Submitting a clean claim the first time avoids the 30- to 60-day resubmission delay that squeezes cash flow in wound care practices.

Modifiers used with CPT 97598

Modifiers add specificity to 97598 claims and are sometimes required to prevent automatic denial. The table below covers the most frequently used modifiers and when each applies.

Who can bill CPT 97598?

The providers eligible to bill CPT 97598 depend on the payer, the billing method, and the clinical setting. Several provider types may bill this code, subject to scope-of-practice rules that vary by state:

• Physicians (MD, DO): May bill directly under their NPI in any covered setting.
• Nurse practitioners and physician assistants: May bill independently in states that permit independent practice. In supervising-physician models, they bill under the supervising physician’s NPI as incident-to services.
• Wound care nurses (RN, LPN): May not bill Medicare directly. Their services are billed under a physician or NPP using incident-to rules, which require the physician to be in the suite and available.
• Physical and occupational therapists: May perform debridement within their scope of practice, depending on state licensure. Their Medicare billing eligibility varies, so verify it with the MAC.

Settings where CPT 97598 may be billed include physician offices, hospital outpatient departments, skilled nursing facilities (SNF), and outpatient wound care centers. Incident-to billing rules are complex, and misapplying them is a frequent compliance finding. Always confirm your MAC’s current incident-to policy before billing 97598 under a supervising provider’s NPI.

How to bill CPT 97598: Step-by-step claim submission

Accurate claim submission for CPT 97598 requires several decisions made before the claim leaves the practice. This step-by-step sequence covers the full process from wound measurement to submission.

1. Measure the wound at the time of the visit. Record length, width, and the calculated cm² in the progress note before any debridement begins.
2. Confirm the debridement technique. Selective debridement by waterjet, irrigation, or scissors, scalpel and forceps uses 97597/97598. Non-selective methods use 97602, and excision into subcutaneous tissue or deeper uses the 1104x series.
3. Calculate units. Subtract 20 cm² (for 97597), divide the remainder by 20, and round up fractions. The result is your 97598 unit count.
4. Select the supporting ICD-10-CM code. The diagnosis must match a wound type covered by your MAC’s LCD. Common codes include L97.x (non-pressure chronic ulcers), L89.x (pressure injuries), and E11.621 (type 2 diabetes with foot ulcer).
5. Attach any required modifiers. Check NCCI edits for bundling conflicts and add -59, -KX, or other modifiers as required by the payer.
6. Complete the CMS-1500 (or equivalent 837P electronic claim). Pair the superbill documentation with the claim before final submission. Bill 97597 on one line, then 97598 with the unit count on the next line.
7. Submit through a clearinghouse. Pabau’s Claim.MD clearinghouse integration routes wound care claims to over 4,000 US payers and validates code pairs. It also returns Electronic Remittance Advice (ERA) 835 files for automated payment posting.

The goal is one auditable package: the clinical note, the code selection, and the claim form, all agreeing before submission. Claims tend to break at two points, the diagnosis pairing in step 4 and clearinghouse validation in step 7. Those two steps cause many of the cash-flow delays in outpatient wound care.

How claims management software prevents CPT 97598 denials

Many 97598 denials start before the claim is built. The wound is measured in one place, the code is picked in another, and the unit count is worked out by hand. When the three disagree, the claim fails an edit or an audit.

In Pabau, the measurement, the CPT code pair and the unit count sit in the same patient record as the progress note. Our claims management software builds the claim from that record. It then sends the claim through the Claim.MD clearinghouse integration, which checks code pairs before the payer sees them.

The result is fewer rejected add-on lines and an audit trail showing how each 97598 unit was earned. Your billing team spends its time on new claims instead of rework.

Automate wound care billing from measurement to claim

Pabau keeps wound measurements, CPT codes and units in the same patient record, then sends wound care claims through its Claim.MD clearinghouse integration.

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Conclusion

Treat the wound measurement as the source document for the claim. If the note records total area, tissue depth and technique, the 97597 and 97598 lines follow directly. An auditor can then rebuild the unit count from the chart.

The trade-off worth remembering is depth. Once tissue removal reaches subcutaneous fat, 97598 is the wrong code however large the wound is, and the 1104x series takes over.

Get those two decisions right at the point of care and the rest of the claim is arithmetic. Book a demo to see how Pabau carries wound measurements from the progress note into a clean 97597 and 97598 claim.

Continue your research

Need a clearinghouse for wound care claims? Medical claims clearinghouse guide explains how clearinghouses validate CPT code pairs and route claims to payers.

Getting repeated denials on wound care billing? Denial codes in medical billing covers the most common CARC denial reasons and how to appeal them efficiently.

Want to verify eligibility before each wound care visit? Insurance eligibility verification walks through the steps to confirm coverage and LCD-qualifying diagnosis codes before the patient arrives.

Is the debridement going deeper than the dermis? CPT code 11043 covers excisional debridement of muscle and/or fascia and how its units are counted.

Switching the wound to negative pressure therapy? CPT code 97605 explains billing for the next active wound care service in the same code family.

Frequently asked questions