Differentiated Instruction (DI) is an approach that recognizes the strengths and weaknesses of diverse learners and requires the teacher to base instructional accommodations on student strengths and weaknesses. Specifically, teachers use DI strategies to adjust the content, process, or product of instruction depending on student needs. Given the complexity of DI as well as the unique situation that alternatively certified teachers face as they enter challenging classrooms with limited experience, they must acknowledge that their learning to teach process will require that knowledge be developed as one practices the profession. This knowledge in practice results from the application of theoretical and research based concepts to one's teaching practice paired with on-going attention to whether the application led to the desired student learning results and, if not, attention to how the practice should be adjusted. Self-regulation may be a tool which helps novices develop the knowledge in practice that strengthens their teaching and student learning. The purpose of this research is to understand alternative certification candidates' development as planners and implementers of DI. The literature already elucidates the importance of developing the professional skills of alternatively certified teachers, and the importance of coaching in learning to plan for high quality instruction. Knowing what factors are critical to learning to plan within the teaching context will make it possible for novices and their supervisors to accelerate novice teachers' success as instructional planners. Furthermore, the conditions made explicit in this study also allows apprentice teachers to be cognizant of the role they play in developing their own planning and differentiation skills. The important role of self-regulation in apprentice development is an overarching conclusion in this study because the development of each of the other conditions (collegial relationships, classroom management, planning for a standard and student need, accepting feedback) was greatly influenced by the apprentice's ability to self-regulate. (Contains 3 figures and 2 tables.)