Most research on early identification of reading disabilities has focused on word reading problems and little attention has been given to reading comprehension difficulties. In this study, we investigated whether measures of language ability and/or response to language intervention in kindergarten uniquely predicted reading comprehension difficulties in third grade. A total of 366 children were administered a battery of screening measures at the beginning of kindergarten and progress monitoring probes across the school year. A subset of children also received a 26-week Tier 2 language intervention. Participants’ achievement in word reading was assessed at the end of second grade, and their performance in reading comprehension was measured as the end of third grade. Results showed that measures of language ability in kindergarten significantly added to the prediction of reading comprehension difficulties over and above kindergarten word reading predictors and direct measures of word reading in second grade. Response to language intervention also proved to be a unique predictor of reading comprehension outcomes. Findings are discussed in terms of their relevance for the early identification of reading disabilities.