We used survey and administrative data from Washington State to assess the degree to which special education teacher preparation, district literacy instructional practices, and the alignment between preparation and practice were associated with the reading test score gains of students with high-incidence disabilities taught by early-career special education teachers in Grades 4 to 8. These students tended to have larger reading gains when their districts used evidence-based literacy decoding practices (e.g., phonological awareness, phonics, and reading fluency) and when their special education teacher graduated from a teacher education program that also emphasized these practices. Students with high-incidence disabilities in districts that used balanced literacy practices tended to have lower reading gains. Finally, students with high-incidence disabilities taught by early-career special education teachers tended to have larger reading gains when their teacher's student teaching placement was supervised by a more experienced cooperating teacher. [For the corresponding grantee submission, see ED618761.]