This case study describes how Partners HealthCare’s Accountable Care Organization (ACO), a large integrated delivery system participating in the Next Generation ACO (NGACO) Model, implemented the skilled nursing facility (SNF) three-day rule waiver. The Partners HealthCare ACO strategy emphasizes strong communication channels across multiple operating levels: central ACO staff that oversee and support decision-making around appropriate use of the waiver, the partnering local physician organization waiver teams that identify and initiate the waiver process for clinically-appropriate patients, and SNFs that work with the physician organizations to serve patients. Partners HealthCare ACO identified three areas where they learned important lessons: 1) identifying patients who are appropriate for the waiver; 2) dedicating staff to focus on waiver operations; and 3) engaging providers to further the waiver implementation effort. This experience is valuable to ACOs implementing the waiver or seeking to refine the waiver operations strategy.