Young adults have a high societal relevance but are still an under-represented target group in health promotion. Health literacy is widely acknowledged as one of the strongest predictors and key determinant of health, so its influence on work ability is of great interest. The purpose of the study was to examine the associations between health-related skills and work ability within the structural model of health literacy of Lenartz, Soellner and colleagues, which explains health behaviour and health through the indirect and direct influence of six ‘advanced skills’ (‘self-perception’, ‘proactive approach to health’, ‘dealing with health information’, ‘self-control’, ‘self-regulation’ and ‘communication and cooperation’). The cross-sectional study was based on baseline data of a health literacy promotion intervention (495 vocational school students, 59.0% female, age span 18–25 years). Structural equation modelling with partial least squares was used to examine the associations between the six constructs of the model and the Work Ability Index (WAI). Mean WAI score was 39.7 ± 4.5 (51.1% categorized ‘moderate’/‘poor’). Five out of six constructs of the model showed a statistically significant indirect or direct effect, respectively, on work ability. The model explained 24.8% of the WAI score variance. It is crucial to develop and analyse target group-specific health literacy interventions. The model offers new facets in the modelling of health literacy.