ObjectivesEvidence on the work-related societal impact of long-term health-related consequences following SARS-CoV-2 is emerging. We characterize the modified work ability index (mWAI) of employees 6 to 12 months after an acute infection compared to pre-infection. MethodsAnalyses were based on a population-based, multi-center cross-sectional study including employees aged 18-65 years with positive SARS-CoV-2 polymerase chain reaction (tested between October 2020-April 2021 in defined geographic regions in Germany). Prevalences and results of adjusted logistic regression analyses were given. ResultsIn 9752 employees (mean age 45.6 years, 58% females, response 24%), n = 1217 (13.1%) participants were regarded as having low mWAI compared to pre-infection. Outpatient medical treatment, inpatient treatment, and admission to intensive care during infection were associated with mWAI <15th percentile (P15, each odds ratio [OR] >3.0). Post-COVID symptom clusters most strongly linked to mWAI <P15 were neurocognitive impairment and fatigue, but varying according to different age groups, to a lesser extent according to different work demands. Associations for pre-existing mental disorders (OR 3.6 [95% confidence interval 3.0; 4.3]) and mental disorders during/after infection (OR 8.0 [95% confidence interval 6.1; 10.4]) with mWAI <P15 were found. ConclusionOur findings revealed risk factors of mWAI <P15 and associations of post-COVID symptom clusters with WAI <P15, which could be potentially prioritized for targeting rehabilitation measures.