Preservice teacher education programs worldwide are increasingly becoming field based with student teaching as the capstone experience for preservice teacher learning in the program. Consequently, mentor teachers at field-placement program schools are bestowed with new and unique functions to support preservice teachers' learning to teach, which calls for new conceptualizations of teacher mentoring approaches. This article critically examines the theoretical underpinnings of four existing approaches to teacher mentoring during student teaching, analyzes the focuses and practices associated with each approach, and identifies the major challenges that each approach faces in guiding preservice teachers to learn to teach as expected by the field based teacher education reforms. Finally, it proposes an integrated approach to teacher mentoring for field-based teacher education that transcends the four existing teacher mentoring approaches.