The purpose of this study was to provide an overview of caregiver prevalence and characteristics and to estimate the impact of caregiving on health care utilization and expenditures among AARP® Medicare Supplement insureds to inform caregiver intervention strategies. A subgroup with live-in partners was used to investigate the additional effect of live-in health status on caregiver health. Multivariate regression models were utilized to determine caregivers' characteristics and associated impacts on their health care utilization and expenditures. Among respondents (n = 18,928), 14.9% self-identified as caregivers. The strongest characteristics included being younger, healthier, but reporting depression or loneliness. Caregivers of sicker live-ins were female, older and indicated moderate loneliness caregivers of healthier live-ins were younger, healthier, but reported severe loneliness. Caregivers had significantly lower inpatient admissions and medical and prescription drug expenditures. These results indicated an adverse impact on psychological health associated with caregiving but no evidence of a negative impact on physical health.