SNF Minimum Data Set Accuracy and Payment Audits

Every skilled nursing facility stay billed under Medicare Part A is paid according to a case-mix classification that comes from a single clinical assessment: the Minimum Data Set (MDS). Under the Patient Driven Payment Model (PDPM), the codes a facility enters on specific MDS items, not a flat per-diem rate, determine what Medicare pays for that stay. A reviewer examining the claim works from the chart, not the resident, and checks whether the documentation supports the MDS codes the facility used to bill. A mismatch becomes the basis for an overpayment demand, and SNF MDS audits are now a named line in the Medicare audit wave CMS and HHS-OIG are running against Part A providers nationwide.

How MDS Items Set the PDPM Payment Rate

PDPM assigns a Part A stay to five case-mix adjusted components: physical therapy, occupational therapy, speech-language pathology, nursing, and non-therapy ancillary services, plus a sixth, non-case-mix component for room and board. Each component's rate comes from specific coded items on the MDS rather than from a therapy-minutes count, the method the prior RUG-IV system used. Section GG of the MDS captures the resident's functional status on items covering bed mobility, transfers, eating, toileting, and walking, and the Section GG score drives the physical therapy and occupational therapy components directly. The resident's primary ICD-10 diagnosis, also coded on the MDS, sets the clinical category the physical therapy, occupational therapy, and speech-language pathology components use. Other conditions and services coded elsewhere on the MDS set the comorbidity score behind the non-therapy ancillary component. These five components interact across a full Part A stay, covered in Health Law Alliance's overview of skilled nursing facility audits under PDPM.

What a Reviewer Compares to the Chart

A medical review contractor auditing a SNF claim requests the resident's full clinical record for the assessment's observation window, not only the MDS form itself. The reviewer checks each coded Section GG item against the nursing notes, therapy evaluations, and physician documentation from that same window to confirm the resident's functional status matches what the facility reported. The same reviewer compares the primary diagnosis coded on the MDS against the physician's documentation, to confirm it reflects the condition that drove the SNF stay. Medicare's Recovery Audit Contractor (RAC) program and other CMS post-payment review contractors run this same chart-to-code comparison across the claims they sample.

How a Documentation Gap Becomes an Overpayment

When the clinical record does not support a coded MDS item, the reviewer reclassifies the stay into the case-mix group the documentation does support. A lower Section GG score or a different diagnosis category can place the stay in a lower-paying case-mix group, and the difference between what Medicare paid and what the corrected group would have paid becomes the claim-level overpayment. Reviewers evaluating more than a handful of claims draw a sample, calculate an error rate across it, and apply extrapolation to project that rate across every claim the facility billed in the audited period, not only the claims reviewed. The facility then receives a recoupment demand for the extrapolated total on the timeline the audit notice sets, while any appeal proceeds on a separate track.

A Current Example of SNF Payment Enforcement

The HHS Office of Inspector General is running an open audit series examining whether Medicare payments to skilled nursing facilities under PDPM complied with Medicare requirements. In a report issued November 14, 2025, the OIG reviewed 100 sampled skilled nursing claims billed by Pinnacle Multicare Nursing and Rehabilitation Center for calendar years 2020 and 2021 and found that 99 of the 100 claims did not meet Medicare payment requirements. The sample alone carried $1.1 million in overpayments, and the OIG estimated the facility's total overpayment for the period at no less than $31.2 million. The OIG's own finding was that the facility's billing staff did not always follow its procedures for assigning reimbursement rate codes, and did not support those codes against the clinical record.

An OIG report issued November 14, 2025 found that 99 of 100 sampled Pinnacle Multicare claims failed to meet Medicare payment requirements, with estimated total overpayments of at least $31.2 million.

Why Early Legal Counsel Is Critical

It is critical that skilled nursing facilities promptly retain experienced healthcare defense counsel upon receiving an MDS audit notice, a document request, or a recoupment demand. Early legal intervention can help the facility assemble a complete and accurate response, avoid inadvertent admissions about how an assessment was coded, preserve the facility's appeal rights, and allow counsel to communicate with the reviewing contractor on the facility's behalf. Delaying legal representation until after a response deadline passes can significantly narrow these options.

How Health Law Alliance Can Help

Health Law Alliance's attorneys have overseen 2,000+ audits and handled 5,000+ matters, with 25+ years of experience.

Health Law Alliance's skilled nursing facility audit defense attorneys represent SNFs nationwide against MDS-based PDPM audits, from the initial document request through any recoupment appeal. If your facility has received an MDS audit notice or a recoupment demand, contact Health Law Alliance's skilled nursing facility audit defense attorneys for a free, confidential consultation.