Occupational differences in COVID-19 diseases – A wave-specific analysis of 3.17 million insured persons Objective: Previous results on occupational differences in the COVID-19 infection risk are heterogeneous. One reason for this could be the different observation periods of previous studies. Wave-specific analyses are not yet available. The aim of this paper is to investigate COVID-19 disease risks along occupational characteristics for the first four waves of the pandemic. Methods: The study uses health insurance data from the research database of InGef (Institute for Applied Health Research) on more than 3.17 million insured men and women between 18 and 67 years of age. To compare wave-specific associations, a distinction was made between the four main infection waves of the pandemic between 01.01.2020 and 31.12.2021. SARS-CoV-2 infections were determined on the basis of the transmitted COVID-19 diagnoses (ICD codes U07.1!). Occupations were divided according to the four groupings of the official classification of occupations. In addition to wave-specific incidence rates, multivariable Cox regressions were estimated (adjusted for sex, age and region). Results: Personal service occupations (esp. healthcare occupations) showed significantly higher incidence rates, especially at the beginning of the pandemic (waves 1 and 2), but these rates were comparable to those of other occupations with increased risk during the course of the pandemic. Production occupations (especially manufacturing occupations), on the other hand, had rather low incidence rates at the beginning of the pandemic, but higher risks as the pandemic progressed. A kind of reversal from lower to higher incidence rates in the course of the pandemic was also observed for lowskilled occupations or occupations without a management function. Results remained consistent after controlling for sex, age and region. Conclusion: The study shows that occupational differences in COVID-19 incidence varied by pandemic phase. Accordingly, it appears that the risk of infections is partly shaped by the occupation, but also by the extent to which it was possible to establish infection control measures during the pandemic. Keywords: COVID-19 – occupational inequalities – social epidemiology – Germany