This longitudinal study examined the development of reading motivation, engagement, and achievement in early adolescence by comparing interrelations of these variables in struggling and advanced readers. Participants were 183 pairs of seventh grade students matched in gender, ethnicity, socioeconomic status, and school attended. They completed measures of reading motivations, engagement and comprehension for information text as well as measures of general reading comprehension and reading fluency twice during the school year. Advanced readers showed stronger relations of motivation and engagement with achievement than struggling readers. However, motivation predicted concurrent engagement and growth in engagement similarly for struggling and advanced readers. These results are interpreted as support for the hypothesis that cognitive challenges limit the relations of motivation and engagement to achievement for struggling readers. The discussion also considers the impact of the focus on the information text genre on the relations observed and implications of the findings for achievement motivation theories.