PURPOSE: We assessed differences in structural characteristics, quality improvement processes, and cardiovascular preventive care by ownership type among 989 small to medium primary care practices. METHODS: This cross-sectional analysis used electronic health record and survey data collected between September 2015 and April 2017 as part of an evaluation of the EvidenceNOW: Advancing Heart Health in Primary Care Initiative by the Agency for Health Care Research and Quality. We compared physician-owned practices, health system or medical group practices, and Federally Qualified Health Centers (FQHC) by using 15 survey-based practice characteristic measures, 9 survey-based quality improvement process measures, and 4 electronic health record-based cardiovascular disease prevention quality measures, namely, aspirin prescription, blood pressure control, cholesterol management, and smoking cessation support (ABCS). RESULTS: Physician-owned practices were more likely to be solo (45.0% compared with 8.1%, P < .001 for health system practices and 12.8%, P = .009 for FQHCs) and less likely to have experienced a major change (eg, moved to a new location) in the last year (43.1% vs 65.4%, P = .01 and 72.1%, P = .001, respectively). FQHCs reported the highest use of quality improvement processes, followed by health system practices. ABCS performance was similar across ownership type, with the exception of smoking cessation support (51.0% for physician-owned practices vs 67.3%, P = .004 for health system practices and 69.3%, P = .004 for FQHCs). CONCLUSIONS: Primary care practice ownership was associated with differences in quality improvement process measures, with FQHCs reporting the highest use of such quality-improvement strategies. ABCS were mostly unrelated to ownership, suggesting a complex path between quality improvement strategies and outcomes.