The What Works Clearinghouse (WWC) has updated its 2009 intervention report for SuccessMaker®, a set of computer-based courses designed to supplement regular K-8 reading instruction. The program is designed to improve skills in areas such as concepts of print, phonological awareness, phonics, fluency, vocabulary, comprehension, grammar, and spelling. Since the last WWC intervention report, there have been 34 new studies, one of which meets WWC group design standards without reservations. Based on the evidence now available, SuccessMaker® shows no discernible effects on comprehension and reading fluency for adolescent readers. Appended are: (1) Research details for Gatti (2011); (2) Outcome measures for each domain; (3) Findings included in the rating for the comprehension and reading fluency domains; and (4) Description of supplemental findings for the comprehension and fluency domains.