Objective: Clinically significant PMS and its more severe form, PMDD, can affect women mentally and interfere with their ability to work. This study used the Mental Component Summary (MCS) scores to predict work loss risk associated with the two diagnoses. Methods: Two data sources were used. From the Medical Outcome Study (MOS), MCS scores from SF-36 Health Survey was regressed onto three work loss outcomes (inability-to-work-due-to-health-problems at baseline, work loss follow-ups at 6-months and one-year) with age and gender as covariates. In an Internet survey, SF-12 Health Survey and retrospective component of American College of Obstetricians and Gynecologists (ACOG) for identifying “at-risk-for-clinically-significant-PMS” and retrospective criteria in DSM-IV-TR for identifying “at-risk-for-PMDD” were collected from a panel of representative U.S. women 18-45 years (N=971). Given MCS scores from SF-12 in the Survey, regression coefficients derived from MOS logistic regressions were used to generate odds ratios (OR) of work loss risk for women with and without PMS or PMDD. ANOVA tests compared the probability differences in ORs within each diagnosis. Results: A total of 17.7% and 6.0% of women were identified as “at-risk-for-clinically-significant-PMS” and “at-risk-for-PMDD”, respectively. Statistically significant differences were observed in all outcome comparisons in both diagnoses (p<0.001). Women not at risk for either diagnosis had risks of work loss comparable to the general population. Women “at-risk-for-clinically-significant-PMS” had a 74% increased risk of work loss at the concurrent state; those who worked at baseline had 53% and 48% increased risk of work loss at 6-month and 1-year follow-ups. Women “at-risk-for-PMDD” had a 99% increased risk of work loss at the concurrent state; those working at baseline had a 70% and 63% increased risk at respective follow-ups. Conclusion: Using MCS scores, women with either clinically significant PMS or PMDD were more likely to experience work loss than the general population, especially women with PMDD.