Compromised Sustainable Employability (SE) of medical doctors poses a risk to the viability of health care, and consequently, to society’s welfare. In order to address medical doctors’ compromised SE a better understanding of its underlying determinants is needed. Therefore, drawing on the Job Demands-Resources (JD-R) model, extended with Psychosocial Safety Climate (PSC), we tested PSC as a ‘cause of causes’, examining direct and indirect relationships between PSC, job characteristics (job demands and job resources), and SE outcomes (burnout, work engagement, and job satisfaction). We also tested whether PSC moderates job characteristics-SE relationships. Multilevel structural equation modelling was used to analyse questionnaire data from 604 medical doctors across 28 groups. PSC was analysed at the group-level, while other variables were analysed at the individual-level. Results showed that job demands and job resources were related to SE outcomes, generally in line with the JD-R model. PSC was particularly positively related to job resources and negatively to the job demand social harassment. We found some support for indirect relationships between PSC and SE outcomes through job characteristics, as well as PSC’s moderating role on job characteristics-SE relationships. Surprisingly, under high PSC, unfavourable job characteristics were associated with more negative SE outcomes. These findings suggest that healthcare organisations can enhance medical doctors’ SE by fostering a high PSC and designing favourable job characteristics.