To identify caregivers at risk for adverse health effects associated with caregiving, the stress, coping, health and service use of 500 primary caregivers of patients with bipolar disorder were assessed at baseline, 6, and 12 months. K-means cluster analysis and ANOVA identified and characterized groups with differing baseline stress/coping profiles. Mixed effects models examined the effects of cluster, time, and covariates on health outcomes. Three groups were identified. Burdened caregivers had higher burden and avoidance coping levels, and lower mastery and social support than effective and stigmatized caregivers; stigmatized caregivers reported the highest perceived stigma (p < 0.05). Effective and stigmatized groups had better health outcomes and less service use than the burdened group over time; stigmatized caregivers had poorer self-care than effective caregivers. Cluster analysis is a promising method for identifying subgroups of caregivers with different stress and coping profiles associated with different health-related outcomes.