Wound care billing is one of the most technically demanding areas in outpatient coding. The wrong code choice, even by one level of tissue depth, can mean a denied claim, an underpayment, or a compliance flag.

This guide covers the CPT codes that matter most, how to choose between them, what documentation payers expect, and where outpatient wound care claims most often go wrong.

Connecticut Medical Billing has helped wound care providers across CT reduce denials and speed up reimbursement. Contact us for a free consultation at connecticutmedbill.com.

The Foundation: Understanding Wound Type Before You Code

Correct code selection starts with identifying what was actually done to the wound, not what the wound looks like. Payers and auditors evaluate coding based on the tissue level reached and the method used, not the wound’s appearance at presentation.

There are two primary categories of wound care services:

• Active wound care procedures, selective or non-selective debridement in outpatient settings
• Surgical debridement, excision of tissue below the dermis, typically requiring sharper technique and deeper access

Mixing these categories up is the top reason wound care claims are denied or flagged during audit.

Selective Debridement: CPT 97597 and 97598

What These Codes Cover

CPT 97597 and 97598 apply when devitalized tissue is removed from the wound surface, epidermis or dermis, without excising into subcutaneous tissue, muscle, or bone. The procedure involves removal of slough, fibrin, biofilm, or necrotic debris using sharp, enzymatic, autolytic, or mechanical methods.

• CPT 97597, Selective debridement, first 20 sq cm or less per session
• CPT 97598, Each additional 20 sq cm after the first

Report 97597 for the initial wound area and add 97598 for each additional 20 sq cm unit. If treating wounds at multiple anatomical sites in a single visit, use modifier -59 to bypass bundling edits, when that’s clinically appropriate.

Documentation Required for 97597 and 97598

Medicare’s LCD for Active Wound Care Procedures (L35125) requires your documentation to reflect:

• Pre- and post-debridement wound measurements (length x width)
• Description of tissue removed, type, color, and consistency
• Method used, sharp debridement, enzymatic, autolytic, or mechanical
• Wound bed appearance after debridement
• Diagnosis linking the wound to an underlying condition

One common audit trigger: same wound size across multiple visits with no noted progression or change. Always document the healing trajectory, even if progress is slow.

Frequency Limits

Medicare allows selective debridement billing once per week per wound site. Billing more frequently than that without documented clinical justification, such as wound deterioration or significant infection, will result in denial.

Non-Selective Debridement: CPT 97602

CPT 97602 covers wound treatment where the goal is to clean the wound without selective tissue removal. It applies to wet-to-dry dressings, whirlpool therapy, and other techniques that do not selectively target devitalized tissue.

You cannot bill 97602 on the same wound on the same day as 97597 or 97598. Payers treat these as mutually exclusive for the same wound site.

Surgical Debridement: CPT 11042 Through 11047

These codes apply when tissue is excised below the dermis using sharp surgical technique. Code selection depends on the deepest tissue layer reached during the procedure.

The Code Structure

• CPT 11042, Subcutaneous tissue, first 20 sq cm
• CPT 11043, Muscle or fascia, first 20 sq cm
• CPT 11044, Bone, first 20 sq cm
• CPT 11045, Add-on: each additional 20 sq cm, subcutaneous
• CPT 11046, Add-on: each additional 20 sq cm, muscle or fascia
• CPT 11047, Add-on: each additional 20 sq cm, bone

Code to the deepest tissue actually removed, not the wound’s overall depth. A wound that extends to bone but where only subcutaneous tissue was debrided during that session is coded as 11042, not 11044.

Place-of-Service Restrictions

The deeper codes, 11043, 11044, 11046, and 11047, are restricted to inpatient hospitals, outpatient hospital departments, or ambulatory surgical centers. They cannot be billed from a physician’s office. Submitting them with a POS 11 (office) code will result in denial.

Dressings, NPWT, and Advanced Therapies

Dressing Change Billing

Routine dressing changes are generally not separately billable in outpatient settings. When dressings are applied as part of a debridement procedure (97597, 97598, or 97602), the dressing is bundled into those codes and cannot be billed separately.

Complex dressings, such as compression dressings, have specific codes:

• CPT 29580, Application of Unna boot, leg
• CPT 29581, Application of multi-layer compression system, leg

Negative Pressure Wound Therapy (NPWT)

NPWT (wound VAC) has its own CPT codes based on wound size and device type:

• CPT 97605, NPWT, wound area 50 sq cm or less
• CPT 97606, NPWT, wound area greater than 50 sq cm
• CPT 97607, Disposable NPWT, wound area 50 sq cm or less
• CPT 97608, Disposable NPWT, wound area greater than 50 sq cm

Prior authorization is commonly required for NPWT, especially for home use. Document device type, wound size, application time, and clinical rationale in every note where NPWT is billed.

Skin Substitutes and Grafts

Applications of biological skin substitutes have strict compliance requirements. Payers require product name, graft dimensions, wound site, and evidence that standard wound care has been attempted and failed. Medicare has specific Local Coverage Determinations governing skin substitute use, know your MAC’s LCD before billing.

E/M Visits in Wound Care

Evaluation and management codes can be billed alongside wound care procedures when a separately identifiable E/M service occurs at the same visit. The E/M must involve medical decision-making beyond the wound care itself, such as adjusting a medication, reviewing lab results, or addressing a systemic condition.

Attach modifier -25 to the E/M code when billing it on the same day as a wound care procedure. Without it, the E/M will be bundled into the procedure payment.

Not sure if your wound care claims are leaving money on the table? Connecticut Medical Billing offers a free billing review. Visit connecticutmedbill.com to get started.

Hospital Outpatient vs. Physician Office Billing

Where wound care is delivered changes how it is billed. Hospital outpatient departments follow OPPS rules, which package certain services into APC payments. Some services that would be separately billable in a physician’s office become bundled under OPPS.

Physicians billing from a hospital outpatient department also need to use the correct revenue codes and bill type codes. The procedural CPT code may be the same, but the claim form and billing structure differ from a professional office claim.

If your wound care clinic is hospital-based, review your OPPS packaging rules annually, CMS updates them each year in the final OPPS rule.

ICD-10 Codes for Wound Care

The diagnosis code establishes medical necessity. Wound type, location, and underlying cause all affect code selection:

• L97.319, Non-pressure chronic ulcer of right ankle, unspecified severity
• L97.519, Non-pressure chronic ulcer of other part of right foot
• E11.621, Type 2 diabetes with foot ulcer
• L89.213, Pressure ulcer of right hip, stage 3
• T81.31XA, Disruption of external surgical wound, not elsewhere classified, initial encounter

Code to the highest specificity. Unspecified wound codes are acceptable only when the record genuinely does not support a more specific code, not as a default choice.

Most Common Wound Care Billing Errors

Coding Debridement by Wound Depth Instead of Tissue Removed

The CPT code reflects the tissue level actually excised during that session, not the wound’s overall depth. Coding based on wound appearance rather than the procedure leads to overcoding and audit exposure.

Billing 97597 for a Dressing Change

If no selective tissue removal occurred, 97597 does not apply. Billing it for cleansing or dressing application without actual debridement is a compliance issue.

Missing Wound Measurements

Wound size in sq cm determines whether you bill one unit or multiple units for 97597/97598 and the surgical debridement add-on codes. Notes without measurements cannot support the units billed.

Wrong Place of Service for Deep Surgical Debridement

11043 and 11044 cannot be billed in a physician office setting. Claims submitted with POS 11 for these codes will be denied.

Bundling Errors with Multiple Wounds

When treating multiple wounds at the same visit, each separate anatomical site may require modifier -59 or modifier XS to distinguish from bundling edits. Missing these modifiers collapses all wound work into a single payment unit.

Compliance Checklist for Outpatient Wound Care

• Verify insurance coverage and prior authorization before each wound care service
• Document wound measurements (length x width), tissue type, and treatment method at every visit
• Confirm code selection reflects tissue level removed, not wound appearance
• Check NCCI edits when billing multiple wound care codes in one session
• Attach modifier -25 to any E/M code billed same-day as a wound procedure
• Track frequency limits per wound site, especially for Medicare patients
• Review your MAC’s active LCD for wound care annually, LCDs can change

FAQs: Outpatient Wound Care Billing

What is the difference between CPT 97597 and CPT 11042?

CPT 97597 covers selective debridement of tissue at the epidermal or dermal level, it is an active wound care code. CPT 11042 covers surgical debridement of subcutaneous tissue using excisional technique. The choice depends on how deep the debridement went and the method used.

Can dressings be billed separately in outpatient wound care?

Generally, no, when dressings are applied as part of a debridement procedure, they are bundled. Special dressings like compression systems (29580, 29581) or HCPCS supply codes for wound products may be billed separately under certain payer rules.

How many units of CPT 97597 can I bill per visit?

Report 97597 once for the first 20 sq cm. For each additional 20 sq cm after that, add a unit of 97598. Wound measurement documentation must support the total sq cm billed.

Does Medicare require prior authorization for wound VAC?

Prior authorization for NPWT (wound VAC) is common among Medicare Advantage plans and commercial payers. Traditional Medicare fee-for-service does not require it in most cases, but DME suppliers billing for home NPWT units face additional coverage criteria.

What happens if I bill surgical debridement codes from a physician office?

Claims for CPT 11043, 11044, 11046, and 11047 submitted with POS 11 will be denied. These codes are restricted to inpatient hospitals, outpatient hospital departments, and ASCs.

How should I document multiple wounds treated in one visit?

Document each wound separately, anatomical location, size, tissue type, and procedure performed. Use modifier -59 or XS when billing the same CPT code for wounds at separate anatomical sites to prevent NCCI bundling edits from collapsing them.

Can a therapist bill 97597 in an outpatient facility?

Yes, therapists acting within their licensure can bill 97597 and 97598 in outpatient settings, but must attach the appropriate therapy modifier and use the correct therapy revenue code when billing in a Part A outpatient facility setting.

Connecticut Medical Billing specializes in outpatient wound care billing across CT. Get a free consultation at connecticutmedbill.com, and stop leaving reimbursement on the table.