Ms. Samantha Tierney has 20 years of progressive leadership experience in clinical quality measure development, endorsement, and implementation. As a Senior Scientist, Performance Measurement at the American College of Physicians (ACP), she leads the evaluation of measures according to predefined ACP-developed criteria, provides strategic direction related to performance measurement policy, and works to advance measurement science. Previously as Senior Director, measurement science, for the PCPI ® Foundation (formerly the AMA-convened Physician Consortium for Performance Improvement), she provided technical expertise and oversaw staff managing measure development, specification, and testing projects. Ms. Tierney was directly involved in the development of many measures focused on several diseases, including chronic and behavioral health conditions. She has authored publications on performance measurement and is involved in numerous national performance measurement committees.