In this paper, we ask what constitutes effective professional development for teachers faced with struggling readers in high school. Metacognitive teacher training, instructional coaching, mentorship, and collaborative learning are considered. We describe a professional development model preparing high school teachers to teach PHAST PACES, a remedial reading program. A metacognitive teaching style and specific skills for teaching comprehension and decoding strategies were emphasized. Teachers provided high positive ratings regarding the usefulness of the training, and attributed to the training an increased sense of efficacy in improving student outcomes and understanding reading problems. A comparison of student outcomes for teachers' first and subsequent classes suggested that the professional development model promotes better outcomes on more complex skills.