Purpose: The intent of this study was to examine the longitudinal morpho-syntactic progression of children with Speech Sound Disorders (SSD) grouped according to Mean Length of Utterance (MLU) scores. Methods: Thirty-seven children separated into four clusters were assessed in their pre-kindergarten and Grade 1 years. Cluster 1 were children with typical development; the other clusters were children with SSD. Cluster 2 had good pre-kindergarten MLU; Clusters 3 and 4 had low MLU scores in pre-kindergarten, and (respectively) good and poor MLU outcomes. Results: Children with SSD in pre-kindergarten had lower Developmental Sentence Scores (DSS) and made fewer attempts at finite embedded clauses than children with typical development. All children with SSD, especially Cluster 4, had difficulty with finite verb morphology. Conclusions: Children with SSD and typical MLU may be weak in some areas of syntax. Children with SSD who have low MLU scores and poor finite verb morphology skills in pre-kindergarten may be at risk for poor expressive language outcomes. However, these results need to be replicated with larger groups. Learning outcomes: The reader should (1) have a general understanding of findings from studies on morpho-syntax and SSD conducted over the last half century (2) be aware of some potential areas of morpho-syntactic weakness in young children with SSD who nonetheless have typical MLU, and (3) be aware of some potential longitudinal predictors of continued language difficulty in young children with SSD and poor MLU. (Contains 3 tables and 1 figure.)