Background Multimorbidity (the co-occurrence of multiple chronic or long-term diseases or conditions in one individual) is a growing health concern worldwide. Multimorbidity is associated with many adverse health outcomes but its association with working life expectancy (WLE) is unknown.

Methods We used data from Finnish Public Sector Study, a longitudinal study of employees in ten municipalities and 21 public healthcare hospitals in Finland. Multimorbidity was ascertained from nationwide registers and self-reported questions on physician diagnoses of chronic diseases. WLE from age 50 up to 68 years was ascertained from a nationwide register of pensionable earnings. We used multistate models to estimate WLE for individuals with and without multimorbidity, with the analyses stratified by sex and occupational group.

Results In all, 35,980 women and 8,963 men aged ≥50 years in 2000-2016 were included in the analyses. At age 50 years, women who worked in professional jobs and had no disease were expected to continue working, on average, for 13.8 years (95% CI: 13.8 to 13.9), whereas women with ≥3 diseases could expect to work 12.8 years (95% CI: 12.7 to 12.9). The corresponding estimates for professional men were 13.9 years for those with no disease (95% CI: 13.8 to 14.0) and 12.8 years (95% CI: 12.7 to 12.9) for those with ≥3 diseases. The differences between employees with and without multimorbidity were similar across the occupational groups, but the estimated WLEs among those in intermediate and routine jobs were ~1 year lower than among those in professional jobs.

Discussion Our findings suggest that multimorbidity is associated with up to one year’s reduction in WLE across occupational groups among aging public sector workers in Finland.