The bond between client and therapist, a component of the global alliance, is widely believed to play a crucial role in supporting the work of therapy. However, we know little about how the client-therapist bond becomes established and have few theoretical tools to conceptualize its development. Attachment theory, with its focus on the development and dynamics of intimate relationships, is a lens through which we can expand our understanding of the client-therapist bond. I argue that the therapeutic bond may be usefully viewed as an in-progress attachment to therapists. UsingBowlby (1969/1982)and Ainsworth's (Ainsworth et al., 1978) ideas about normative attachment development, I present a phase model of attachment to the therapist and include behavioral, cognitive, emotional, and physiological markers of each phase. I draw empirical support from the psychotherapy process and alliance literatures and discuss research considerations and clinical implications of the model.