The HHS Office of Inspector General’s (“OIG”) September 2026 audit of Methodist Hospital located in San Antonio, Texas (“Hospital”) shows how a relatively small claim review can lead to a much larger repayment recommendation when OIG identifies billing patterns it considers high risk. OIG reviewed 100 inpatient and outpatient claims, found 27 did not fully comply with selected Medicare billing requirements, and calculated $256,926 in net overpayments in the sample. Using statistical extrapolation, OIG estimated at least $12.4 million in net overpayments within a $62 million sampling frame. That figure is an OIG recommendation, not a final Medicare overpayment determination.
OIG did not select the Hospital at random. As part of a broader hospital compliance-audit initiative, OIG used “computer matching, data mining, and other data analysis techniques” to identify hospitals with disproportionate numbers of claims in areas previously associated with billing errors. The Hospital was selected because it had a “substantial number” of claims in those areas. OIG emphasized, however, that submitting claims in these risk areas “does not by itself mean the claims were noncompliant” and that its audit was not an overall assessment of all claims submitted by the hospital.
The risk areas included Inpatient Rehabilitation Facility (“IRF”) claims; inpatient claims involving selected diagnosis-related
groups (“DRGs”), mechanical ventilation, severe malnutrition, same-day discharge and readmission, and resumption of home health; and certain outpatient billing patterns. OIG’s findings included disputed IRF medical-necessity determinations, unsupported diagnosis and procedure codes, unsupported outlier billing, an incorrect discharge-status code, unsupported outpatient Healthcare Common Procedure Coding System (“HCPCS”) coding, and an outpatient medical-necessity issue. OIG concluded that the errors occurred primarily because hospital staff did not consistently follow existing policies and procedures.
The Hospital disputed significant portions of the audit, including OIG’s IRF findings and its positions on reopening and extrapolation. After considering the hospital’s response, OIG removed two Two-Midnight Rule claims and reduced its recommended recovery from about $13.5 million to about $12.5 million.
Hospital leadership should consider providing this report to the hospital’s compliance and internal-audit teams and asking whether the same risk areas, documentation issues, and data patterns could exist within their own Medicare claims. In particular, hospitals may want to consider whether their internal analytics can identify unusual billing patterns before an external reviewer does.
Members of Butler Snow’s Health Law Group are available to assist hospitals with questions about the OIG report, Medicare billing and compliance issues, internal audits, or related matters.
