The results of the study of the classification of occupational safety costs, in particular the classification of costs for medical examinations, according to the current requirements of the regulatory legal acts and documents of the Republic of Kazakhstan are presented. The Labor Code of the Republic of Kazakhstan does not regulate the cost of financing occupational safety costs in the organizations. In addition, there are no state-approved methodology for planning and occupational safety budgeting costs. International research in the field of occupational safety confirms the positive effect of the investments in occupational safety on the competitiveness, productivity, and sustainability of the enterprise at the market. At the same time, the methodologically sound organization of planning and financing of occupational safety costs depends on their correct classification, which further contributes to the construction of a rational budgetary system of the enterprise in the field of occupational safety. The need for cost classification is due to the fact, that the existing occupational safety activities have different signs and types of costs. In the process of the study the empirical data is used, for example, codes, laws, and other regulatory legal acts of the Republic of Kazakhstan, as well as the scientific research from near and far abroad. The paper offers three signs of the classification of occupational safety costs. In accordance with the proposed signs of cost classification, the types of medical examinations that employers are legally required to conduct for their employees are distributed. Thus, the classification of occupational safety costs, which is aimed at the cost management, should consider all the main options for solving managerial tasks of the enterprise in the field of occupational safety, and should be applicable in practice. At the same time, the classification of costs with varying degrees of detail contributes to the sound planning and financing of the costs for employee occupational safety, which will lead to a positive result from the investment.