For plans effective January 1, 2012, Medicare Part D members could choose a closed formulary prescription drug option through the AmeriHealth Rx PDP Option 1 plan. Unlike an open formulary, where all Part D-eligible drugs are covered, a closed formulary is a cost-effective option with a limited selection of prescription drugs. The drugs covered under the closed formulary are carefully chosen by our Pharmacy and Therapeutics Committee for their medical effectiveness, safety, and value. Prior to prescribing medication to a Medicare Part D member, please be sure to verify coverage for the medication. Many Medicare Part D members who had an open formulary for 2011 have migrated to a closed formulary for their 2012 benefits. Drug-specific coverage information can be found at Find a Drug or Pharmacy web page on amerihealthmedicare.com.