Purpose: We identified the types of home-and community-based services (HCBS) that high-risk older adults in Medicare managed care used, and we examined participant characteristics associated with service use in six areas: overall service use, four specific categories of HCBS, and referrals to insured medical services. Design and Methods: We used service data from the Care Advocate Demonstration Program, a telephone-based care-management intervention that linked chronically ill older adults to HCBS. Two hundred and twenty-four high-risk older adults who were enrolled in a southern California-based Medicare managed care plan received an assessment, service referrals, and 12 months of telephone follow-up by master's level social service professionals. We used logistic regression to estimate the odds of using the HCBS categories and medical services. Results: Results indicated that characteristics associated with service use varied extensively, depending on the service. Age, gender, social support, living situation, education, specific functional impairments, heart conditions, and sensory impairments at baseline significantly predicted utilization in the six different service models. Implications: Policy implications include the importance of individualized care-management assessments that direct targeted referrals to appropriate services. Findings support the need for individualized care-management assessment and service planning, suggesting that a "one size fits all" approach to HCBS will not meet the varied needs of diverse consumers. (Contains 3 tables and 2 figures.)