Purpose: The purpose of this study was to characterize the lexical-morphological networks of children with specific language impairment (SLI) compared to children with typical language by analyzing responses on a morphological derived form production task. Method: School-age children with SLI (n = 32) and peers with typical language (n = 40) completed an oral cloze derived form production task (Carlisle, 2000). On this task, children were expected to complete verbally presented sentences with a derived form of a provided morphological stem. Responses were coded as correct or incorrect following Carlisle's (2000) stated correct responses. Incorrect responses were coded as scorable or unscorable, and then scorable responses were coded as pseudowords or real words. Real words were further coded according to whether they were repetitions of the given stem. Results: There was a statistically significant between-group difference for mean correct responses (d = 1.43). The scorable incorrect responses of children with SLI included a lower mean proportion of pseudowords than did the incorrect responses of children with typical language (d = 0.76). Conclusion: Because children with SLI produced a lower proportion of pseudowords as scorable incorrect responses than peers with typical language, we conclude that they have less developed lexical--morphological networks and, thus, less derivational morphology knowledge than peers with typical language.