Background: Provider wellbeing is a barometer of the strength of healthcare systems/organizations. Burnout prevalence among physicians exceeds that among other adult workers in the United States. Rural-based practitioners might be at greater risk. Objective: We investigated predictors of burnout among group-employed providers within an integrated healthcare network. Methods: In a prospective observational study of physicians/advanced-practice clinicians serving an 8-county region of central New York, we linked administrative practice-setting data with responses to a questionnaire-survey comprising validated measures of burnout, resilience, work meaningfulness, satisfaction, risk aversion, and uncertainty/ambiguity tolerance. We included providers on the official payroll, excepting advisory board and/or research team members plus those who retired, resigned or were fired. 308 (65.1%) of 473 eligible clinicians completed the survey. 59.1% of these were physicians/doctoral-level practitioners; 40.9% advanced-practice clinicians. We assessed burnout using a validated 5-level single-item measure formatted as a binary outcome of "burned out/burning out" (levels 3-5) versus not. We derived a parsimonious generalized linear mixed-effects regression of this outcome on provider demographics, work-related needs, risk aversion, satisfaction, and unit characteristics. Results: Perceived workload, relatedness needs, practice satisfaction ≥ 75% of the time, dissatisfaction ≥ 50%, resilience, and practicing on a small unit were the significant, independent predictors. Conclusions: Heavy workloads, unmet relational needs, frequent dissatisfaction, low resilience, and serving on a small unit were most significantly associated with being "burned out/burning out". Feeling satisfied most of the time and high resilience were protective. Profession, specialty, autonomy, and support staffing were not statistically significant.