An increasing adoption of teams is observed in provisions of care for chronically ill patients. There is growing interest in the role that relationship plays in the care process. Understanding processes of care delivered by teams, especially teams attuned to enhance the relationship as a means for delivering quality care, is necessary. This study explores the use of lay health workers, called care guides, to form goal-oriented, relationship-focused care teams in primary care settings. I assess the effect of adding lay health workers to primary care teams in improving quality of care for chronically ill patients through the mediating variable of continuity of care and moderating variable of relational coordination. This research used data from a randomized controlled trial comparing patients working with lay health workers, care guides, added to the primary care team (intervention group) and those receiving usual care (comparison group) for one year. The study setting was five primary care clinics in a single delivery system in Minnesota. The primary outcome was the receipt of recommended care for hypertension, heart failure, and diabetes. Summary outcomes were expressed as the percentage of guideline adherence to recommended care. The measure of relational coordination was comprised of five items derived from the Relational Coordination Survey. Continuity of care was calculated using a record of each ambulatory visit, weighting both the frequency of visits and the dispersion of visits between providers. Multiple-group structural equation modeling was extended to path models to examine the influence of relational coordination and continuity of care on the effectiveness of care guides on adherence to guideline-recommended care, controlling for baseline adherence. The result showed that care guides had a differential effect on adherence to quality care measures depending on the levels of relational coordination in the sites of care. The findings suggest that a good fit between the context of coordination and the mechanisms of coordination is required. Understanding the influence of contextual factors such as the strength and the quality of relationships on goal-directed team care for chronic disease patients will be instrumental in the design of future care team models that seeks to change work processes and organizational structures to support more effective chronic disease management and teamwork.