As part of the reporting of Delaware's State Improvement Grant (DelaSIG), the Delaware Education Research and Development Center (R&D Center) completed a study on the Diagnostic Assessment of Reading (DAR) scores of students whose teachers attended a professional development program designed to help focus teacher instruction of struggling readers in Grades 4 through 12. IMPACT, the acronym for Implementing Multiple Practices for Activating Comprehension in Teaching, is a 30 hour training component of the professional development program provided by the Delaware Department of Education (DDOE). This paper reports the findings of the fall and spring assessments of the DAR and discusses their results and implications. Program developers may find the perceptions of the IMPACT survey respondents informative; their perceptions regarding the influence of the IMPACT training on their classroom instruction and on their students' reading provide insight into the context of the findings. Appended are: (1) Individual student results on the DAR; and (2) DAR-IMPACT Survey Protocol and Results. (Contains 8 figures, 5 tables, and 4 footnotes.) [This report was written with assistance from Debra Coffey and Ximena Uribe-Zarain.]