The Centers for Medicare & Medicaid Services (CMS) released the calendar year (CY) 2027 Hospital Outpatient Prospective Payment System (OPPS) and Ambulatory Surgical Center (ASC) final rule on November 4, 2026. The final rule includes policies affecting hospital outpatient departments (HOPDs), provider-based physician practices, and ASCs, most of which take effect January 1, 2027. CMS continues to pursue several long-term priorities, including expanding site-neutral payment policies, shifting care to lower-cost outpatient settings, increasing oversight of provider-based departments, and reducing Medicare spending while preserving beneficiary access to care. CMS also finalized significant changes to 340B drug reimbursement and continued the multi-year phaseout of the Inpatient Only (IPO) list, creating new opportunities for outpatient procedural care.