Poster presented during the ISPOR 14th Annual International Meeting 2009 (International Society for Pharmacoeconomics and Outcomes Research) titled “Medicare Part D’s Effect On Prescribing Volume: Average Monthly Utilization of Selected High Use Drugs In The Six Protected Classes, By Different Specialties”. The authors, led by Quintiles Consulting Principal Consultant Craig White, assess whether the implementation of Medicare Part D coverage affected trends in average per physician prescription volume of select drugs in six classes deemed by CMS/Medicare Part D to be medically necessary for reimbursement. They also investigate how prescribers of different specialties were affected over the 2005-2008 period.