Purpose: This Phase II treatment study examined the effect of Verb Network Strengthening Treatment (VNeST) on individuals with moderate-to-severe aphasia. Research questions addressed (a) pre- to posttreatment changes and pretreatment to treatment phase changes on probe sentences containing trained verbs (e.g., "The carpenter is 'measuring' the stairs") and semantically related untrained verbs (e.g., "The nurse is 'weighing' the baby"); (b) lexical retrieval changes in single-word naming, sentence, and discourse measures; (c) functional communication by way of proxy and participant report; and (d) error evolution. Method: A multiple-baseline approach across participants was used. Effect sizes were calculated for pre- and posttreatment and maintenance probe responses. A "C" statistic was used to determine changes from the baseline to treatment phases. Results: One participant exhibited improvement on all generalization measures, whereas the other participant exhibited more limited generalization. Both participants showed improvement on the functional communication measure. Conclusions: As predicted, the participants did not show the same extent of improvement that was observed in participants with more moderate aphasia (Edmonds, Nadeu, & Kiran, 2009). Nonetheless, the findings suggest that VNeST may be appropriate for persons with moderate-to-severe aphasia, especially with a small adaptation to the treatment protocol that will be retained for future iterations of VNeST. (Contains 4 tables and 3 figures.)