This randomized controlled trial is evaluating the effectiveness of a pilot-tested, manualized cognitive remediation intervention entitled the "Thinking Skills for Work Program" by comparing it to enhanced supported employment services in clients with severe mental illness (SMI) who are participants in high fidelity supported employment programs at the Greater Mental health Center of Manchester and Thresholds, Inc., Chicago, Il, but who have had difficulty getting or keeping jobs. Participants are randomized to either the Thinking Skills for Work (cognitive remediation +supported employment; CT+SE) or enhanced supported employment (E-SE), with cognitive, symptom, and quality of life assessments performed at baseline, 3 months (following the completion of the computerized cognitive training component of the Thinking Skills for Work program), 12 months, and 24 months, and employment data gathered over the full 2-year period. For the E-SE condition, supported employment services are enhanced by training provided to the employment specialists regarding to recognize cognitive problems related to work performance, and how employment specialists can teach clients coping strategies for managing these problems. Primary analyses will focus on testing the hypotheses that the Thinking Skills for Work Program (CT+SE) leads to better cognitive functioning and better competitive work outcomes over the 2-year follow-up period compared to the E-SE program.