Structural equation modeling evaluated the contribution of phonological, orthographic, morphological, and oral vocabulary factors to word reading, spelling, and reading comprehension outcomes in 98 2nd graders at risk for passing state standards in reading and to those same outcomes plus composing in 97 4th graders at risk for passing state standards in writing. For 2nd-grade children, morphology contributed uniquely to reading comprehension, and oral vocabulary and orthography contributed uniquely to word reading. For 4th-grade children, morphology and oral vocabulary did not contribute uniquely to any outcomes, but morphology and word reading were correlated, and orthography and phonology contributed uniquely to decoding words with affixes. Fourth graders are still learning to coordinate orthographic, phonological, and morphological cues in written words. (PsycINFO Database Record (c) 2016 APA, all rights reserved)