Using structural equation modeling the authors evaluated the contribution of morphological awareness, phonological memory, and phonological decoding to reading comprehension, reading vocabulary, spelling, and accuracy and rate of decoding morphologically complex words for 182 4th- and 5th-grade students, 218 6th- and 7th-grade students, and 207 8th- and 9th-grade students in a suburban school district. Morphological awareness made a significant unique contribution to reading comprehension, reading vocabulary, and spelling for all 3 groups, to all measures of decoding rate for the 8th/9th-grade students, and to some measures of decoding accuracy for the 4th/5th-grade and 8th/9th-grade students. Morphological awareness also made a significant contribution to reading comprehension above and beyond that of reading vocabulary for all 3 groups.