This study describes what types of service use barriers older adults' informal care-givers perceive and examines how these barriers differentiate care-giver service use patterns. Analysing the 2004 National Long-Term Care Survey and Informal Care-giver Data Set (N=1908) in the United States of America, this study reports the prevalence of service barriers for each type of service as well as for overall service use. Service barriers are measured in terms of availability, awareness, affordability, staff quality, privacy violation, complex bureaucracy, language barriers, qualification of each programme and no thought of service. Andersen's health behaviour model guides determinants related to care-giver service use patterns. As a main outcome, care-giver service use patterns (light service users, selective in-home users, and multiple service users) are examined in relation to service use barriers when other predisposing, enabling and need variables are controlled. Of the ten service use barriers defined in this study, awareness and no thought of service are the most prevalent barriers. Care-givers reporting service barriers of availability, awareness and affordability are more likely to be light service users compared to multiple service users and selective in-home service users. These findings highlight the significance of enhancing awareness of care-giver supportive services as well as increasing availability and financial support for service use.