Blue Shield of California’s 2013 Medicare Advantage HMO and Medicare Part D prescription drug plans received four stars for program quality from the Centers for Medicare & Medicaid Services (CMS). This is the second year in a row CMS awarded Blue Shield of California a 4 Star rating. CMS measures the quality and performance of Medicare health and prescription drug plans using more than 50 metrics such as keeping members healthy, managing chronic conditions, plan responsiveness, customer service, pricing and safety, and pharmacy services. Plan performance Star Ratings are assessed each year and may change from one year to the next according to a report in the Sacramento Bee.