When people think of sex discrimination, they tend to think of glass-ceiling discrimination and sexual harassment. This article describes and documents a rapidly expanding area of employment discrimination law: family responsibilities discrimination, or "FRD." FRD is employment discrimination against people based on their caregiving responsibilities, whether for children, elderly parents, or ill partners. FRD includes both "maternal wall" discrimination -- the equivalent of the glass ceiling for mothers -- and discrimination against men who participate in childcare or provide care for other family members.