A skin substitute audit no longer stops at the medical record. Unified Program Integrity Contractors (UPICs) and Medicare Administrative Contractors now routinely request the practice's purchasing records, order forms, supplier invoices, and rebate agreements for the products billed, and they compare the units purchased against the units billed to Medicare over the same period. Medicare Part B spending on skin substitutes surpassed $10 billion in 2024, and HHS-OIG flagged the trend as a fraud, waste, and abuse concern in a September 2025 report. A wound care practice that cannot produce clean purchase records to match its billing is exposed to recoupment, referral, and False Claims Act liability well beyond the individual claims the audit names.
Why Auditors Request Purchase Records
A skin substitute document request typically asks for a full year of purchasing records: order forms, manufacturer or distributor invoices, and any rebate arrangements tied to the products at issue. Auditors read these records against the claims data, not in isolation. The purchase record establishes a ceiling on what the practice could have legitimately applied to patients during the period. When the billed unit count for a graft product exceeds what the practice's own purchase history supports, the gap becomes the audit's central finding rather than a side note.
The Purchase-to-Billing Shortfall
This comparison is the shortfall theory: if a practice billed Medicare for more square centimeters of a graft than it purchased from its suppliers over the same lookback period, the shortfall stands in for direct proof that some billed applications did not occur as documented. The theory does not require an auditor to prove intent at the document-request stage. It only requires the arithmetic, purchased units against billed units, to come out negative. That is why a practice's internal inventory tracking, not just its clinical notes, decides how an audit resolves.
A gap between the units a practice purchased from its suppliers and the units it billed to Medicare over the same period is not a bookkeeping footnote. It is the finding.
Supplier Records as Independent Corroboration
Supplier invoices and order forms carry weight that a practice's own chart notes do not, because a third party generated them and a practice cannot revise them after the fact. A local coverage determination sets the medical-necessity and coding criteria a claim must satisfy, but it is the supplier's own paper trail that tells an auditor whether the product needed to meet that criteria actually existed in the practice's hands on the date of service. Rebate agreements draw particular scrutiny, since a rebate structure that effectively lowers the practice's net acquisition cost below the billed Medicare rate raises a separate line of inquiry under the Anti-Kickback Statute.
Aligning the Medical Record With the Purchase Record
Closing the gap before an auditor finds it starts with recording, for every application, the product name, manufacturer, and lot or serial number in the patient's chart, alongside the wound measurements that support the graft's size. Coding for the graft application and any accompanying debridement should trace back to the same lot-level record used in the purchasing log, so a reviewer can move from invoice to chart to claim without a gap at any step. Practices already under prepayment review face this reconciliation on every claim before payment, which makes the underlying inventory discipline a condition of cash flow, not just audit defense.
Why Early Legal Counsel Is Critical
It is critical that wound care providers promptly retain experienced healthcare defense counsel upon receiving a skin substitute audit notice, subpoena, or other investigative request. Early legal intervention can protect the provider's rights, ensure appropriate responses to government and contractor requests, avoid inadvertent admissions in how purchase and billing data are explained, preserve relevant defenses, and allow counsel to communicate with the auditor on the provider's behalf. Delaying legal representation can significantly affect the outcome of a matter and expose the provider to unnecessary risk.
How Health Law Alliance Can Help
Health Law Alliance defends wound care providers against skin substitute audits, UPIC and MAC document requests, and the recoupment and False Claims Act exposure that follows a purchase-to-billing shortfall finding. Our team reconstructs the purchase record, the lot-level clinical documentation, and the coding history into a single defensible account before the government does it first. If your practice has received a skin substitute audit notice or document request, contact us for a free, confidential consultation.
