One dimension of language proficiency considered important for reading and writing academic texts is morphological awareness--the understanding of how complex words are formed from meaningful smaller units (i.e., affixes, roots) that contribute to words' meanings and functions. This quasi-experimental study evaluated the effects of instruction on syntactic and relational aspects of morphological awareness for language minority (LM) learners (n = 349) and native English speakers (n = 133) in grade 6. In 7 urban middle schools, teachers implementing an 18-week multicomponential academic language intervention were matched to teachers providing the standard curriculum to students with similar achievement and demographics. Multilevel modeling indicated statistically significant, practically meaningful effects on morphological awareness. For relational aspects, LM learners and their peers demonstrated similar gains. For syntactic aspects, LM learners demonstrated greater gains than their peers. Findings suggest the potential benefits of incorporating morphology into academic language instruction, particularly for LM learners. (Contains 6 tables and 6 notes.)