Team-based care has emerged as a promising strategy for primary care practices to provide high-quality care. We examine changes in patient experience of care and recommended cancer screening rates associated with a primary care transformation initiative that established team-based care. Our observational study included 13 academically affiliated primary care practices in the Boston, Massachusetts area that participated in 2 learning collaboratives: the first (2012-2014) aimed to establish team-based primary care, while the second (2014-2016) focused on improving patient safety and cancer screening. We identified 37 comparison practices of similar size and network affiliation. Using a difference-in-differences approach, we compared pre (2013) and post (2015) patient experience and recommended cancer screening rates between intervention and comparison practices. We estimated linear regression models, using inverse probability weighting to balance on observable differences. Massachusetts Health Quality Partners data on patient experience comes from surveys (with communication, integration, knowledge of patient, access, office staff, and willingness to recommend domains), and its data on screening rates for breast, colorectal, and cervical cancers is derived from chart abstraction. Relative to comparison practices, the communication score in intervention practices increased by 1.47 percentage points on a 100-point scale ( P = .02) between pre and post periods. We did not detect immediate improvements in other measures of patient experience of care and recommended cancer screening rates. Communication may be the first dimension of patient experience that improves following establishment of team-based primary care, and changing care processes may require more time or attention in the transition to team-based care. Our findings also suggest a need to better understand the variation in implementation factors that facilitate some practices’ successful transitions to team-based care, and to use teams effectively to improve cancer screening processes.