Many educators are unprepared to meet the needs of students with the most intensive reading intervention needs. The purpose of this review was to identify how researchers have provided professional development (PD) to support educators' implementation of intensive reading interventions, the extent to which these approaches included essential PD elements, and how researchers have measured implementer outcomes. In the 26 studies reviewed, implementers received initial training, and most received some form of ongoing support. Most studies appeared to incorporate one or more essential PD elements, though many lacked sufficient detail regarding the presence of these elements. Researchers used a variety of fidelity measures and other methods to assess implementer outcomes, which were typically positive. Results of this review indicate the need for researchers to report more detailed descriptions of PD activities, as well as the need for continued research on how best to support teachers' implementation of intensive reading interventions.