Alta Bates Summit Medical Center, a 354-bed hospital in Oakland, Calif., failed to comply with Medicare billing requirements for 46 of 100 inpatient and outpatient claims reviewed by HHS' Office of Inspector General, according to an OIG report.
The one outpatient and 45 inpatient claims that had billing errors resulted in the hospital receiving $1.6 million in combined overpayments during the audit period of Jan. 1, 2017, through Dec. 31, 2018, according to the OIG.
Extrapolating from the sample results, the OIG estimated Alta Bates Summit Medical Center received $16.4 million in overpayments from Medicare during the audit period.
Based on its findings, the OIG recommended the hospital refund Medicare $16.3 million in estimated overpayments. The hospital has already refunded more than $49,000. The OIG also recommended that the hospital exercise reasonable diligence to identify and return any additional overpayments and strengthen controls to ensure full compliance with Medicare requirements.
In written comments on the draft report, the hospital disagreed with most of the OIG's findings and recommendations, including the OIG's extrapolation, audit timing and methodology.
After reviewing the hospital's comments, the OIG maintained its findings and recommendations.