Welcome to the fourth practice-based research theme issue published in as many years by the Journal of the American Board of Family Medicine. Practice-based research is receiving increased attention and funding nationally. Research conducted through practice-based research networks (PBRNs) continues to grow in the complexity of its research questions, the diversity of study participants, and the sophistication of interventions. In this issue we present original research and scholarly contributions with a broad range of design methodologies, including randomized trials, descriptive epidemiology, cross-sectional surveys, fascinating case studies, and important commentaries.