This document shows the market share of electronic health record vendors by practice size, ranging from solo practices of 1-3 physicians to large practices of 41 or more physicians. Epic has the largest overall market share at 10.3% and is most popular among medium to large practices. Allscripts has the second largest overall share at 10.6% and leads in the smallest practices. Market share varies significantly depending on practice size, with no single vendor dominating across all categories.