"Reading Mastery" is designed to provide explicit reading instruction to students in grades pre-K-5. One of several Direct Instruction curricula from McGraw-Hill, "Reading Mastery" is available in two versions: (1) "Reading Mastery Classic" (for grades pre-K-2) aims to help beginning readers identify letter sounds, segment words into sounds, blend sounds into words, develop vocabulary, and begin to learn comprehension strategies. "Reading Mastery Classic" consists of two levels. "Reading Mastery Fast Cycle" is an accelerated program that condenses Levels I and II; (2) "Reading Mastery Signature Edition" (for grades K-5) is organized by grade level and includes three strands: Reading, Language Arts, and Literature. The Reading strand addresses phonemic awareness, phonics, word analysis, fluency, vocabulary, comprehension, spelling, decoding, and word recognition skills. The Language Arts strand focuses on oral language, communication, and writing skills. The Literature strand is designed to provide students with opportunities to read different types of text and to develop their vocabulary. "Reading Mastery" can be used as a supplement to a core reading program or as a stand-alone reading program for students with or without disabilities. This intervention report specifically focuses on the use of "Reading Mastery" to improve the reading and writing skills of students with learning disabilities. Seventeen studies reviewed by the What Works Clearinghouse (WWC) investigated the effects of "Reading Mastery" on students with learning disabilities. Two studies (Cooke, Gibbs, Campbell, & Shalvis, 2004; Herrera, Logan, Cooker, Morris, & Lyman, 1997) are randomized controlled trials that meet WWC evidence standards without reservations. These two studies are summarized in this report. The remaining 15 studies do not meet either WWC eligibility screens or evidence standards. Appended are: (1) Research details for Cooke et al., 2004; (2) Research details for Herrera et al., 1997; (3) Outcome measures for each domain; (4) Findings included in the rating for the alphabetics domain; (5) Findings included in the rating for the reading fluency domain; (6) Findings included in the rating for the reading comprehension domain; and (7) Findings included in the rating for the writing domain. A glossary of terms is included. (Contains 8 tables, 6 endnotes and 1 additional source.)