How OIG Used Data Analytics And Extrapolation In A $12.4 Million Hospital Audit

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