For this effort to be successful, 3 principles are important. First, bundles should encompass a broad range of medical conditions, not a select few. Second, given that 30 days is an arbitrary line in the sand and lacks a clinical basis (making it too long for some conditions and too short for others), the length of the bundle should be clinically guided and empirically derived. An average patient admitted with pneumonia may take as long as 45 or 60 days before he or she is back to baseline, whereas a patient admitted for gastrointestinal hemorrhage might return to baseline within 15 days. Finally, a robust set of quality measures—not just mortality but also complications, functional status, pain, patient experience—must be tied to bundled payments, so hospitals don’t save money by skimping on care.