Women who provide care for children and adults who need it forgo an average of $295,000 in lifetime income. Our estimates of the lifetime employment-related costs to women of providing care, expressed in inflation-adjusted 2021 dollars, are based on simulations from Urban’s Dynamic Simulation of Income Model. Eighty percent of the cost ($237,000) results directly from lost lifetime earnings. That $237,000 represents 15 percent of what we project mothers would earn, on average, if they did not provide family care. The remaining 20 percent of lifetime costs results from lost retirement income from Social Security and employment-based retirement plans, which averages $58,000 over a lifetime. These findings highlight the importance of caregiver supports, such as affordable childcare, for women with young children.