Background/Objectives: Social support can prevent or delay long-term nursing home placement (NHP). The purpose of our study was to understand how the availability of a caregiver can affect NHP after ischemic stroke and how this affects different subgroups differently. Design: Nested cohort study. Setting: Nationally based REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Participants: Stroke survivors aged 65 to 100 (256 men, 304 women). Measurements: Data were from Medicare claims from January 2003 to December 2013 and REGARDS baseline interviews conducted from January 2003 to October 2007. Caregiver support was measured by asking, “If you had a serious illness or became disabled, do you have someone who would be able to provide care for you on an on-going basis?” Diagnosis of ischemic stroke was derived from inpatient claims. NHP was determined using a validated claims algorithm for stays of 100 days and longer. Risk was estimated using Cox regression. Results: Within 5 years of stroke, 119 (21.3%) participants had been placed in a nursing home. Risk of NHP was greater in those lacking available caregivers (log-rank P =.006). After adjustment for covariates, lacking an available caregiver increased the risk of NHP after stroke within 1 year by 70% (hazard ratio (HR) = 1.70, 95% confidence interval (CI) = 0.97–2.99) and within 5 years by 68% (HR = 1.68, 95% CI = 1.10–2.58). The effect of caregiver availability on NHP within 5 years was limited to men (HR = 3.15, 95% CI = 1.49–6.67). Conclusion: In men aged 65 and older who have survived an ischemic stroke, the lack of an available caregiver is associated with triple the risk of NHP within 5 years.