Family and friends provide substantial daily assistance to older adults with disabilities, but little is known about how that caregiving impacts the health of older adults. Using survey data on a nationally-representative sample of older adults and their caregivers, matched with Medicare claims, I explored several aspects of the relationship between caregiving and the health of older adults receiving care. I relied largely on Andersen’s behavioral model, which describes health services use as a product of predisposing, enabling, and need characteristics. I found that 33%-37% of older adults with unmet care needs at one point in time still have them one year later. I also found frequent change in the composition of older adults’ networks of caregivers. Having a formal caregiver was associated with lower odds of unmet care needs for women; conversely, men receiving care from a spouse had three times lower odds of unmet care needs than those receiving care from a non-spousal caregiver. Some caregivers use services such as respite care, training, and support groups, but some caregivers lack access to desired services. I found that caregivers reporting unmet service need were more likely to be Black and Hispanic, while service use was higher among caregivers providing help on a regular schedule. Care-recipient health and function was associated with both service use and unmet service need, but available measures of local caregiver service supply were not. Older adults frequently seek care in emergency departments (EDs), but this care may not always be necessary or desirable. I hypothesized, but did not find, that caregiver service use was associated with care-recipient ED use. Instead, chronic health conditions and other need factors were the strongest predictors of ED use. I found that care-recipients of male caregivers had lower rates of ED utilization for reasons that were urgent and not preventable. I also found that care-recipients of adult children had lower rates of non-urgent ED utilization than care-recipients of more distantly-related or unrelated caregivers. These findings suggest that unmet care needs might be reduced by improving access to formal care for older women with functional limitations and monitoring unmarried older men. In addition, improving service access for Black and Hispanic caregivers, and for caregivers who provide unscheduled care, could reduce caregivers’ unmet service need. Finally, targeting training and support services to male spousal caregivers could improve access both to needed daily care and to emergency care. Future research should focus on replicating these analyses after more data become available and on developing alternate measures of caregiver service supply.