Using a nationwide sample of 2656 eighteen- to twenty-nine-year-olds, the first part of the present study addressed the question of how non-traditional as compared to traditional living arrangements related to young people's self-perception of being either adolescent or adult. Being in a romantic relationship increased the likelihood of feeling adult. Modern adult living arrangements (living alone in a single household or sharing an apartment with peers) increased the likelihood of feeling adolescent. Employing a longitudinal sample of 461 twenty- to twenty-seven-year-olds, changes in job status and sources of income were studied with regard to their connections to the emergence of subjective adulthood or the regression to subjective adolescence, respectively. No association between adult or adolescent self-perception and issues of work and material autonomy was found, but the emergence of subjective adulthood was related to romantic relationships and parenthood. Findings are discussed with reference to young people's volatile living conditions and transient commitments implied by social change.