Schizophrenia presents a substantial clinical and economic burden to the health-care system. In QUAlity of LIfe with AbiliFY Maintena (QUALIFY), a randomized head-to-head study of aripiprazole once-monthly 400 mg (AOM 400) compared with paliperidone palmitate (PP; 78–234 mg/mo), AOM 400 demonstrated greater improvement in health-related quality of life and functioning in patients with stable schizophrenia. The present analysis used health economics assessment data collected during the QUALIFY study to determine the direct medical and pharmacy costs and the cost-effectiveness associated with each treatment over 6 months. Compared with those receiving PP, patients receiving AOM 400 incurred significantly lower direct total costs ($8908±186 vs $9675±190, p=0.005) and treatment costs ($7967±113 vs $8706±116, p<0.001). Effectiveness results in the subset of patients included in the cost analyses were similar to the overall population: mean (95% CI) improvement in Heinrichs-Carpenter Quality of Life Scale total score was greater with AOM 400 (5.97 [3.87; 8.08]) compared with PP (2.85 [0.56; 5.08]). Likewise, Clinical Global Impression–Severity improved more in the AOM 400 group (–0.59 [–0.71; –0.47]) compared with PP group (–0.37 [–0.46; –0.27]). Therefore, the analysis of data from stabilized patients with schizophrenia in the QUALIFY study indicated that AOM 400 is associated with lower health-care costs and greater effectiveness compared with PP and thus represents the economically dominant strategy.