This longitudinal study investigated growth in reading-related skills between Grade 1 and 4 for language minority (LM) learners and their native English-speaking classmates from similarly low socioeconomic backgrounds (N = 166). Growth trajectories were compared by language background and by Grade 4 reading difficulties, with the goal of informing decisions about how early LM learners can undergo screening for risk of reading difficulties. As a group, LM learners demonstrated weaknesses in vocabulary and oral comprehension and strengths in phonological awareness that were apparent in Grade 1 and consistent through Grade 4. LM learners also demonstrated early strengths in letter-word identification but fell far below national norms by Grade 4. The subset of LM learners with word reading difficulties demonstrated major weaknesses in vocabulary, oral comprehension, phonological awareness, and working memory, whereas LM learners with specific reading comprehension difficulties demonstrated major weaknesses in vocabulary and oral comprehension; these weaknesses were apparent in Grade 1 and consistent through Grade 4, suggesting the importance of early assessment and intervention.