CMS released the calendar year 2024 proposed rule for Medicare’s hospital outpatient prospective payment system (OPPS) and ambulatory surgical center (ASC) payment system (CMS-1786-P) on July 13, 2023. Policies in the proposed rule will generally go into effect on January 1, 2024, unless otherwise specified. The proposed rule was published in the July 31, 2023, issue of the Federal Register. The public comment period will end on September 11, 2023. The proposed rule updates OPPS payment policies that apply to outpatient services provided to Medicare beneficiaries by general acute care hospitals, inpatient rehabilitation facilities, inpatient psychiatric facilities, long-term acute care hospitals, children’s hospitals, and cancer hospitals, as well as for partial hospitalization services in community mental health centers. Also included is the annual update to the ASC payment system and updates and refinements to the requirements for the Hospital Outpatient Quality Reporting Program and the ASC Quality Reporting Program. The 2024 OPPS proposed rule also includes a number of other provisions such as the implementation of an intensive outpatient program, changes to the hospital price transparency program, Medicare payment for dental services, and others. CMS also requests public comment on providing payment incentives for hospitals to maintain a buffer stock of essential medicines. Based on the public comments received on this topic, CMS may adopt provisions in the final rule to go into effect as soon as cost reporting periods beginning on or after January 1, 2024, even though CMS has not made any formal proposals.