This paper presents an ecologically informed approach to conceptualizing and studying the transition to formal teaching of alternative certification candidates. This perspective acknowledges that transitions play an important role in later teaching success; theorizes that a full understanding of teacher competence must examine the influence of the relationships among candidate characteristics and peer, mentor, instructor, and school site contexts. This approach recommends that future policy, practice, and research be based on the following three premises. First, the transition to teaching must be conceptualized in terms of relationships between candidates and their surrounding contexts, especially mentors. Second, that Vygotsky's sociocultural theory takes a closer look at social relationships that foster development (Crain, 2000). Third, the examination of this transition period must address how contexts and relationships develop, and how change and stability in these relationships form key aspects of candidates' transition to teaching.