Bundled payment implementations hinge on coordinating what’s included, how costs are measured across settings, and how the involved providers are aligned. The major challenges fall into five interconnected areas: defining the episode boundaries—deciding which services and time frame are part of the bundle; aggregating costs across settings—patients move across hospitals, clinics, home health, and post-acute care, so you need a consistent way to pull together costs from multiple settings; data sharing—providers must exchange timely, accurate information to plan, monitor, and report performance; ensuring provider alignment—many clinicians and facilities must agree on shared goals, workflows, and how savings or risk are shared; and patient selection—ensuring the bundled population is appropriate and not incented to exclude higher-risk patients. The other options miss these core aspects: marketing-episode boundaries aren’t about care episodes; assuming cost data will be accurate isn’t realistic, but accurate data is essential; and assuming lack of provider alignment isn’t a concern is simply false.