This study examined whether children's outcomes at age 3 were predicted by their experiences in Early Head Start (EHS), focusing on 2 key features of infant and toddler care: (a) stability of care and (b) teacher-child interactions. This study further explored potential interaction effects between stability of care and teacher-child interactions in predicting child outcomes. Three main results were found from secondary analyses of the recently released EHS longitudinal data set the EHS Family and Child Experiences Study (Vogel & Boller, 2009–2012). First, children who had stability of care (no teacher change) were rated as having fewer behavior problems and higher social competence. Second, children were rated as demonstrating better orientation/engagement and emotional regulation when they were in EHS classrooms observed to have higher emotional and behavioral support. Third, teacher-child interactions that are emotionally and behaviorally supportive may mitigate the potential drawbacks of experiencing instability of care on early social-emotional development. Study implications are discussed. Practice or Policy: Both stability and quality teacher-child interactions are important in center-based infant and toddler care, and ensuring quality teacher-child interactions is particularly important for children who experience teacher changes during their infant and toddler years. (author abstract)