Work environments and practice structural features are associated with both burnout and the ability of practices to enhance quality of care. To characterize factors associated with primary care practices successfully improving quality scores without increasing clinician and staff burnout. This cross-sectional study assessed small- to medium-sized primary care practices that participated in the EvidenceNOW: Advancing Heart Health initiative using surveys that were administered at baseline (September 2015 to April 2017) and after the intervention (January 2017 to October 2018). Data were analyzed from February 2022 to January 2023. The primary outcome of being a quality and well-being positive deviant practice was defined as a practice with a stable or improved percentage of clinicians and staff reporting burnout over the study period and with practice-level improvement in all 3 cardiovascular quality measures: aspirin prescribing, blood pressure control, and smoking cessation counseling. Of 727 practices with complete burnout and aspirin prescribing, blood pressure control, and smoking cessation counseling data, 18.3% (n = 133) met the criteria to be considered quality and well-being positive deviant practices. In analyses adjusted for practice location, accountable care organization and demonstration project participation, and practice specialty composition, clinician-owned practices had greater odds of being a positive deviant practice (odds ratio, 2.02; 95% CI, 1.16-3.54) than practices owned by a hospital or health system. In this cross-sectional study, clinician-owned practices were more likely to achieve improvements in cardiovascular quality outcomes without increasing staff member burnout than were practices owned by a hospital or health system. Given increasing health care consolidation, our findings suggest the value of studying cultural features of clinician-owned practices that may be associated with positive quality and experience outcomes.