A wound care practice that bills negative pressure wound therapy (NPWT) supplies under a durable medical equipment (DME) code the same period it bills a wound care visit for the same wound is describing two different products. An auditor reading the claims side by side often cannot tell that from the codes alone. Medicare's NPWT local coverage determination (LCD L33821) sets specific rules for wound documentation, how long therapy can run before it needs re-justifying, and which billing track a given device belongs to. A missed monthly wound measurement or a supply billed against the wrong device type is enough to trigger a full-claim review, and the recoupment on NPWT claims can reach back across the entire audit lookback period.
Two Billing Tracks for the Same Therapy
A durable NPWT pump (HCPCS E2402) and its dressing and canister supplies (A6550, A7000) are billed under the DME benefit, on a written order, with the supplier's own ongoing coverage file. A disposable NPWT device is a different product entirely: it is billed under professional per-session codes CPT 97607 and 97608, which already bundle the device, the dressing change, and the wound assessment into one payment. Coders who treat a disposable system as though it were the durable pump, and bill DME supply codes on top of the per-session code, create the exact duplicate-billing pattern a payer's edit system is built to catch.
Duration of Use and the Monthly Reassessment
LCD L33821 conditions continued coverage on quantitative wound measurements (length, width, depth, and exudate volume) recorded at least monthly, showing the wound is still healing. Coverage ends once the wound has healed enough that NPWT is no longer reasonable and necessary, or once a full month passes without measurable improvement. The DME supplier is expected to obtain the treating clinician's assessment of that healing progress, tied to the measurements in the medical record, before billing another month of therapy. A gap in the monthly measurement, documented in our companion piece on wound care LCD compliance, is one of the most common reasons an NPWT claim gets pulled into post-payment review.
Where DME and Professional Billing Collide
The audit risk concentrates at the seam between the two tracks: the same wound, the same treatment period, billed once through a DME supplier number and again through a professional wound care claim. A practice documenting a debridement or a wound care visit for a wound already under an active pump rental needs the record to show the visit addressed something the DME billing did not already cover, not a re-description of the same NPWT management the supplier is separately reimbursed for. A signature log tying each date of service to a specific clinician and a specific note, rather than a batch attestation signed weeks later, is often the first document a UPIC or Medicare Administrative Contractor requests once it flags an overlap between the two billing tracks. Our guide to UPIC audits of wound care practices covers what typically triggers that review.
A wound billed through both a DME supplier and a wound care practice without a monthly measurement documenting why NPWT is still necessary is a claim Medicare can recoup regardless of whether the therapy worked.
Why Early Legal Counsel Is Critical
It is critical that wound care providers promptly retain experienced healthcare defense counsel upon receiving an audit notice, a records request, or any other government inquiry that references NPWT billing. Early legal intervention can protect the provider's rights, ensure the response addresses the documentation and duration-of-use record actually at issue, avoid inadvertent admissions, and preserve defenses that a delayed response can forfeit. Delaying legal representation can significantly affect the outcome of the matter.
How Health Law Alliance Can Help
Health Law Alliance defends wound care providers against audits built on NPWT documentation and DME overlap findings, from the initial records request through appeal of an extrapolated recoupment. Our bench includes attorneys who have handled the LCD-driven audit patterns that concentrate in this space. If your practice has received an audit notice referencing negative pressure wound therapy claims, contact our wound care audit defense team for a free, confidential consultation.
