The Centers for Medicare & Medicaid Services (CMS) issued a final rule addressing significant, anomalous, and highly suspect (SAHS) billing activity within Accountable Care Organizations (ACOs) in the Medicare Shared Savings Program (SSP). In 2023, CMS identified a concerning rise in urinary catheter billings, which was attributed to a small group of durable medical equipment supply companies. CMS determined that the beneficiaries did not receive catheters and were not billed directly, physicians did not order these supplies, and supplies were not needed. This rule specifies how CMS will calculate various factors used in SSP financial calculations for 2023. The proposed Physician Fee Schedule addresses SAHS billing activity for 2024 onwards. As of January 2024, over 500 Critical Access Hospitals and 2,500 Rural Health Clinics participated in Medicare SSP ACOs.