Most classrooms in the U.S. are composed of students with different learning styles and experiences as well as different achievement levels (Ferguson, 2001). Personalized learning is a unique way of students' learning determined by their own learning style, pace, and needs. Focusing on individual differences, personalized instruction aims to accommodate a variety of students to help them achieve mastery learning and performance (Ferguson, 2001). It is hard to promote students' personalized learning if there is no support for teachers' personalized instruction. The flexibility that technology brings to personalized instruction can help teachers contextualize their teaching practice for student diversity and student accountability for learning (Smith & Throne, 2009). However, the availability of technology itself does not promise effective technology integration for personalized instruction. There is a need for professional development that helps teachers learn to utilize technology for personalized instruction (Fok & Ip, 2006). In this article, the authors propose design guidelines for teacher professional development that aim to promote personalized instruction using a recommendation system. (Contains 2 tables.)