The current investigation sought to extend prior research evaluating the use of the PEAK Relational Training System as a comprehensive treatment model in improving language skills demonstrated by individuals with autism. Baseline PEAK-Direct Training and Verbal Behavior Milestone Assessment and Placement Program (VB-MAPP) assessments were conducted across 3 adult male participants, and scores on the PEAK-Direct Training assessment were used to select targets for intervention. Language instruction guided by the PEAK-Direct Training module was implemented for 45 to 69 days across participants. Results suggest that participants mastered target skills throughout the training phase, and VB-MAPP test probes showed an increasing trend. Follow-up probes suggested that scores on the VB-MAPP maintained when training was discontinued. In addition, participants demonstrated an increase in assessment scores on the PEAK-Direct Training assessment in the follow-up phase, including the mastery of untargeted verbal skills.