Health care organizations in the United States face challenges in delivering high-quality primary care. 1,2 For reform measures to successfully improve health, affordability, and patient experience, as well as meaning in work for providers, the care delivery system must be transformed. 3 The patient-centered medical home (PCMH) model is a leading effort to improve quality of care 4-6 by reorganizing a practice's care delivery process to promote comprehensive care, patient-centeredness, care coordination, accessible services, safety, and high-quality care. 7 The model offers many pathways to reduce costs and improve quality, but evidence of its impact is mixed. [8][9][10][11][12] Due in part to variations in the amount and types of practices implemented, PCMH implementation varies significantly by site, with practices undergoing many changes. 13 Although there is no single way to achieve PCMH transformation, there is concordance in the main implementation steps. 9,14 PCMH recognition and certification require that core criteria are satisfied; they also provide various optional criteria. 15 Practices target PCMH changes that are required for recognition and utilize a variety of quality improvement (QI) activities for PCMH transformation. Practices are required to collect and use patient experience surveys and other data to improve their care and services. Which QI activities and PCMH changes are most useful is unclear. [16][17][18] Research has examined organizational climate, 19 QI culture, 20 structural factors associated with PCMH changes, 21 and which PCMH implementation resources are widely used, 16 but it has not studied these factors alongside a validated measure of PCMH implementation with established psychometric qualities. One such measure is the PCMH Assessment (PCMH-A), a proxy for patient-centeredness that measures the degree of PCMH implementation at the practice level. 22 PCMH-A scores are higher for recognized PCMH practices than for nonrecognized practices. 23 In this study, we investigate QI practices and PCMH changes associated with higher levels of PCMH transformation using the PCMH-A.