Purpose: Both fictional oral narrative and expository oral discourse skills are critical language competencies that support children's academic success. Few studies, however, have examined African American children's microstructure performance across these genres. To address this gap in the literature, the study compared African American children's microstructure productivity and complexity across three discourse contexts: fictional narratives, informational discourse, and procedural discourse. The study also examined whether there were age-related differences in microstructure performance by discourse type. Method: Participants were 130 typically developing African American children, aged 59-95 months old, enrolled in kindergarten through second grades in a Midwestern U.S. public school district. Wordless children's books were used to elicit fictional narratives, informational, and procedural discourse. Indicators of microstructure performance included measures of productivity (i.e., number of total words and number of different words) and complexity (i.e., mean length of communication unit and complex syntax rate). The effects of genre and age on microstructure performance were assessed using linear mixed-effects regression models. Results: Children produced longer discourse and used a greater diversity of words for their fictional stories compared to their informational or procedural discourse. Grammatical complexity was greater for fictional narratives and procedural discourse than informational discourse. Results showed greater productivity and complexity among older children compared to younger children, particularly for fictional and informational discourse. Conclusions: African American children exhibit variation in their microstructure performance by discourse context and age. Understanding this variation is key to providing African American children with support to maximize their oral language competencies.