The present study examined the career construction theory (CCT) model of adaptation using a sample of working adults diagnosed with Chiari malformation. Specifically, we tested a mediation model in which adaptivity (i.e., proactivity, openness, and conscientiousness) fosters adaptability, which conditions adapting (i.e., competence need satisfaction at work), which leads to adaptation (i.e., work well-being and subjective well-being). Results of structural equation modeling supported all of the hypothesized direct and indirect relations between CCT constructs, thus providing strong support for the applicability of the model of adaptation among workers with Chiari malformation. Prior to testing the model of adaptation, we examined and found support for the hypothesized hierarchical structure of the Career Adapt-Abilities Scale–Short Form, a recently developed operationalization of career adaptability.