In Health Affairs, Jalpa Doshi and colleagues, including Pengxiang Lee, Andrea Troxel and Kevin Volpp, evaluate whether renewing all medications at the same time from the same pharmacy improves adherence to medication regimens. Synchronizing medication refills is an increasingly popular strategy, but there has been little research regarding its effectiveness. The authors looked at a pilot refill synchronization program implemented by Humana, a large national insurer, and analyzed patients’ adherence before and after participation in the program, compared to a control group. The pilot program ran between September 2013 and December 2014 among beneficiaries enrolled in Medicare Advantage Prescription Drug plans and participating in the Humana Pharmacy mail-order service. A random sample of patients receiving refills for common maintenance medications (antihypertensive, lipid-lowering, or antidiabetic agents) were invited to join the program (691 did) and followed for 12 months. On average, the absolute increase in the proportion of patients deemed adherent during follow-up was 3–10 percentage points for the intervention group, compared to 1–5 percentage points for the control group. Patients with poorer baseline adherence showed larger increases in the absolute proportion deemed adherent in intervention (23–26 percentage points) compared to a control group (13–15 percentage points).