Abstract Background To investigate the impact of changes in employment status and their interaction with alcohol consumption on health outcomes among young workers. This study aims to explore how employment fluctuations, periodic unemployment, and economic activity levels influence the health of economically active individuals, focusing particularly on the synergistic effects that these employment changes may have when combined with alcohol consumption. Methods We conducted a retrospective cohort study using data from the Korean National Health Insurance Service database. The study included individuals aged 25-44 years who underwent health check-ups between 2009 and 2010. We categorized changes in employment status into three groups: continuously employed, economically active with employment fluctuations, and periodically unemployed. We estimated adjusted hazard ratios and 95% confidence intervals using multivariable Cox proportional hazard models to assess the impact of changes in employment status on the risk of all-cause mortality. The relative excess risk due to interaction, a widely accepted indicator of additive interaction, was used to assess the interaction between alcohol consumption and changes in employment status. Results Changes in employment status significantly increased the risk of all-cause mortality in both men and women in the economically active with employment fluctuations and periodically unemployed groups compared with the continuously employed group. The synergistic effect of alcohol consumption and changes in employment status on the risk of all-cause mortality was significant only among men. Conclusions The findings of this study indicate that changes in employment status, particularly when combined with alcohol consumption, significantly affect all-cause mortality among young workers. Key messages • Employment status fluctuations combined with alcohol consumption significantly increase all-cause mortality risks among young workers, especially men. • This study emphasizes the urgent need for targeted interventions that address the combined impact of employment and lifestyle factors on public health.