Guduguntla V, et al. – This cohort study evaluated coronary artery bypass grafting (CABG) payment variation and its drivers by using Medicare and private payer claims. Observations revealed wide variation in 90–day CABG episode payments for Medicare and private payer patients in Michigan. Hospitals and clinicians entering bundled payment programs for CABG should work to understand local sources of variation, with a focus on patients with multiple readmissions, inpatient evaluation and management services, and postdischarge outpatient rehabilitation care.