Job search, job placement, and on-the-job supports are valuable services provided to many people with intellectual and developmental disabilities (IDD) to obtain work in the community. Investigating those who were unemployed at the time of service entry, this study seeks to extend understanding about the effect of services. Using extant data, a sample of 39,277 people with IDD using Vocational Rehabilitation services were studied to understand the potential cumulative effects of these job-related services and individual characteristics on job attainment. Findings showed people with IDD of different demographic groups had different outcomes. Also, those receiving three job-related services were 16 times more likely to obtain employment than the reference group. This study has wide implications for research, policy, and practice.