Little is known about how, when, or why individuals with intellectual and developmental disabilities (IDD) retire. Recognizing the changing needs of older adults with IDD is critical to support person-driven services and development of best practices in aging transitions. Using secondary analysis of the 2016 to 2017 National Core Indicators–Adult Consumer Survey (NCI-ACS) data for adults with IDD, we examined the relation between independent mobility (i.e., without aids), age group, level of intellectual disability, and type of employment/activity program, with a focus on mobility and community-based employment in older age groups. There was an overall age-related decline in mobility, but the prevalence of mobility impairment by age group was related to employment type. The percentage who were independently mobile was highest for community employment in every age group. The percentage of individuals by age group in community employment fell significantly from middle age onward, suggesting some former community-based workers had retired. There was no significant age-related difference in the percentage in facility-based employment across these age groups. Mobility limitations may be a barrier to obtaining or retaining community-based employment. Age-related mobility impairment may be associated with premature retirement, and could affect travel to and from work, undertaking work tasks, or both. Closer examination is needed of aging, community employment, and age-related mobility limitations to understand the specific causes of these effects on employment and identify supports and accommodations.