To adjust future care policies for an ageing population, policy makers need to understand when and why older adults rely on different sources of care (e.g. informal support versus formal services). However, previous scholars have proposed competing conceptualisations of the link between formal and informal care, and empirical examinations have often lacked a dynamic approach. In this study, we applied an analytical method (sequence analysis), allowing for an exploratory and dynamic description of care utilisation. Based on 15 years of data from 473 community-dwelling older individuals in Denmark, we identified four distinct clusters of care trajectories. The probability of belonging to each cluster varied with predisposing factors (such as age and gender), needs factors (such as dependence in activities of daily living and medical conditions) and enabling factors (such as co-habitation and contact with adult children). A key finding wasthat trajectories characterised by sporadic use of informal care were associated with low needs and strong social relations, whereas trajectories characterised by reliance on formal care were associated with high needs and limited contact with children. Taken together, our findings provide new evidence on the associations between care use and multiple determining factors. The dynamic approach to studying care use reveals that sources of individual care utilisation change over time as the individual and societal determinants change.