The 12 regional Medicare Administrative Contractors (MACs) were recently audited by the U.S. Department of Health and Human Services’ Office of Inspector General (OIG). Each of the MAC jurisdictions was found by the OIG to have failed to meet Medicare cost report oversight requirements in at least one year during the 2019-2021 fiscal years under audit.
OIG commented on the importance of cost reports to the Medicare program in order to set accurate future payment rates and wage indexes. The deficiencies found in the audit included improper or inadequate reviews and incorrect classifications of charges to cost centers.
MAC officials blamed the findings in part on the lack of clear guidance from the Centers for Medicare & Medicaid Services (CMS). CMS has agreed with OIG’s findings and recommends specific efforts to improve performance, including increasing transparency and providing additional training.
OIG’s report is dated March 2025 and can be found at oig.hhs.gov.
