This paper addresses the mechanisms leading to income differences during the early career, both between individuals and between occupations. It compares the level ofstandardization, vocational specificity, and vertical differentiation of vocationaleducation and training (VET) programmes and examines how these differences affectVET diploma holders’ incomes in their early careers. We go beyond previous researchby developing refined theoretical concepts of vocational specificity, standardization,and differentiation and by measuring them with novel curriculum-based data.Theoretically, the paper assumes that training programmes’ institutional characteristicsdetermine income by influencing diploma holders’ productivity as well as the signallingpower of the degree. We test our hypotheses by combining institutional data from VETcurricula with individual-level data from the Swiss Labour Force Survey and byapplying multilevel regression analyses. The results show that the institutionaldimensions, in particular vocational specificity, are multifaceted and consist of severalsubdimensions, which impact young workers’ incomes to different degrees at varioustime points during their early careers.