BACKGROUND: Mineralocorticoid receptor antagonists (MRAs) are disease-modifying agents indicated for heart failure (HF) that can augment diuresis and treat hypokalemia but are underutilized. Prescribing MRAs instead of potassium supplements to treat hypokalemia in the setting of HF could increase the use of MRAs. A best practice alert (BPA) in the electronic medical record that suggests ordering an MRA instead of potassium supplementation for a HF patient with hypokalemia could facilitate this. OBJECTIVES: This study sought to examine perspectives of primary care physicians on MRA utilization and BPA usefulness and to develop a novel conceptual model for guiding future BPA development. METHODS: We conducted one-on-one semistructured interviews with primary care physicians until we reached thematic saturation to understand facilitators and barriers of MRA prescription, BPA usage, and our specific BPA. Two coders independently reviewed each interview transcript using directed content analysis. Codes were collated into subthemes and themes. RESULTS: We interviewed 10 participants. We mapped our themes onto the Capability, Opportunity, Motivation, Behavior (COM-B) model, a well-established model that focuses on influential factors of behavior change. Based on these findings, we created a BPA-specific framework that reflects the necessary components for changing medication-prescribing behavior. CONCLUSIONS: We generated a conceptual model to guide development of future BPAs focused on changing medication-prescribing practice based on the COM-B model, using MRAs as a prototype for development.