The strong association of early language skills to later reading ability suggests that supporting the development of these skills in children who enter preschool or kindergarten with below-average language abilities may lead to stronger reading skills. Despite this, few evidence-based supplemental language instructional programs exist for school-based implementation. The current study reports on two large-scale randomized trials of combinations of small-group, intensive language-focused instructional component lessons implemented in preschool and kindergarten settings. After screening on two listening comprehension measures, 740 preschool and 870 kindergarten children were randomized to business-as-usual general education or to 18 weeks of instruction that paired two of three possible 9-week component programs. Children were assessed pre- and postinstruction on a battery of proximal, instructionally aligned measures and on standardized language and early literacy measures. Results indicated significant and often sizeable impacts on measures aligned with the content of instruction received. Moderation by order of instructional components and child characteristics provides insight into the overall and specific benefits of early intensive support for language development.