This study examines the transition from independent living to a coresidential living arrangement across the late life course among older unmarried (i.e., widowed, divorced/separated, and single) Mexican Americans. Using 18 years’ worth of panel data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly, event history analyses revealed that age at migration, physical disability, and cognitive impairment were strong predictors of the transition to a coresidential living arrangement. Importantly, a decline in physical and cognitive abilities heightened the risk of transition to a coresidential living arrangement, net of time-variant measures of disability and impairment. These findings provide evidence for incorporating a dynamic approach to examining living arrangements across the late life course for Mexican-origin Hispanics living in the United States, with implications for policy and service providers.