This article identifies practice- and physician-related characteristics associated with the increased use of EHRs by physicians in outpatient practices. Two Florida surveys conducted in 2005 and 2008 on physician use of EHRs were examined to determine the practice and physician characteristics associated with increased EHR use over time. Based on multivariate analysis, several variables were found to influence increased EHR adoption. Practice variables included participation in a single-specialty practice and percentage of Medicare patients in the practice, but not percentage of Medicaid patients in the practice. Physician characteristics included younger physician age, but not specialty nor years practicing in the community. Factors associated with EHR adoption at any given point in time did not necessarily predict longitudinal increases in EHR adoption. These results are important for physicians to consider in their potential adoption of EHRs and should also be considered by policymakers interested in promoting increased use of EHRs by physicians.