Objectives. Aging-related changes in motivation and the availability of resources have been hypothesized to result in social network changes in later life. However, few studies have examined associations of both motivation and resources with different aspects of social network composition in the same analytical context. The present study examined associations of key motivational (future time perspective [FTP]) and resource variables (partner status, physical health, and perceived neighborhood cohesion) with social network size and positive and negative social exchanges. Method. A population-based sample of midlife (aged 55–59 years, n = 169) young–old (aged 60–74 years, n = 306) and old–old (aged 75+ years, n = 77) adults completed a questionnaire. Results. Those who were partnered reported larger networks with family, whereas never-married individuals reported larger networks with neighbors. Perceived neighborhood cohesion was related to larger networks with family, neighbors, and friends. Open-ended FTP was associated with larger networks of friends and more frequent positive social exchanges. Discussion. Our results point to FTP and resources having different implications for social engagement across network domains.