Lone motherhood is often associated to factors that increase women’s risk of developing poor health, such as being unemployed or poor. Employment fosters better physical health by attenuating economic hardship and improving overall well-being. However, employment can also represent an additional stress factor for lone mothers who face the dual role of main caregiver and main earner. Taking a life course perspective, we investigate how employment associate to self-assessed health of lone mothers in comparison to mothers living with a partner. In Switzerland, weak welfare provisions for families, expensive public childcare, and marriage- based taxation translate into a high incompatibility between work and family, in turn resulting in high shares of maternal part-time work. In this context, being a lone mother might be associated with worse health. Our analyses of the Swiss Household Panel (waves 1999-2011) compared lone mothers and mothers living with a partner, suggesting that lone mothers who are out of the labor market, especially those holding an upper-secondary degree, have a higher probability of poor health. We found that lone mothers working full-time were in better health than those working part-time but that the opposite applied to mothers living in couples. We argue that the negative association between health and paid work for lone mothers is the result of intersections between employment, education, and lone parenthood in a context of poor welfare support.