Optimizing medication use through the evaluation of Potentially Inappropriate Medications (PIMs) has been the focus of a great deal of research. The Centers for Medicare & Medicaid Services (CMS) has created its own definition of PIMs from a variety of existing criteria and has contracted with each state's Quality Improvement Organization (South Dakota Foundation for Medical Care in South Dakota) to work on reducing PIM rates. In South Dakota, 16.4 percent of Medicare beneficiaries who filled a prescription (April 1, 2008, through September 30, 2008) received a PIM. Of the patients receiving PIMs, 13.6 percent received PIMs from two or more categories, and 88.3 percent filled a prescription for at least one of the five most common PIM categories. These five PIM categories were propoxyphene, skeletal muscle relaxants (select agents), nitrofurantoin, oral estrogens and antihistamines (select agents). While there may be rare occasions when these agents are justified, safer or more effective alternatives exist.