Employees’ wellbeing and performance are two important indicators of the sustainability of their careers. Research has generally assumed a synergetic relationship between performance and wellbeing, but empirical results have been inconsistent. In the present study, we used the relationship between performance and wellbeing as a proxy for sustainable careers, examining the effects of different HR practices and age on career sustainability. Data came from two waves of 653 employees and their supervisors in 26 organizations in Spain. To test the hypotheses we performed cluster and multinomial regression analyses. Results showed no positive, direct, relationships between HR practices and a sustainable career pattern. However, we found interactions between age and six HR practices in their relationship with four wellbeing-performance patterns. Performance appraisal, recruitment and selection, security, and exit management were more beneficial to younger employees, whereas contingent pay and competitive salary were more beneficial to older employees. Thus, this study highlights that HRM and age are antecedents of employees’ wellbeing and high performance, that is, a sustainable career. It enhances our understanding of the role of HR practices in career sustainability and shows the value of a contingency approach to HR.