Objective-This report describes the characteristics of primary care physicians in patient-centered medical home (PCMH) practices and compares these characteristics with those of primary care physicians in non-PCMH practices. Methods-The data presented in this report were collected during the induction interview for the 2013 National Ambulatory Medical Care Survey, a national probability sample survey of nonfederal physicians who see patients in office settings in the United States. Analyses exclude anesthesiologists, radiologists, pathologists, and physicians in community health centers. In this report, PCMH status is self-defined as having been certified by one of the following organizations: Accreditation Association for Ambulatory Health Care, The Joint Commission, National Committee for Quality Assurance, URAC, or other certifying bodies. Estimates exclude physicians missing information on PCMH status. Sample data are weighted to produce national estimates of physicians and characteristics of their practices. Results-In 2013, 18.0% of office-based primary care physicians worked in practices certified as PCMHs. A higher percentage of primary care physicians in PCMH practices (68.8%) had at least one physician assistant, nurse practitioner, or certified nurse midwife on staff compared with non-PCMH practices (47.7%). A higher percentage of primary care physicians in PCMH practices reported electronic transmission (69.6%) as the primary method for receiving information on patients hospitalized or seen in emergency departments compared with non-PCMH practices (41.5%). The percentage of primary care physicians in practices reporting quality measures or quality indicators to payers or organizations monitoring health care quality was higher in PCMH practices (86.8%) compared with non-PCMH practices (70.2%).