Despite the stigma, millennials may have a good reason for living under their parents’ roof. If millennials living at home in South Florida were to move out, U.S. Census Bureau data indicates that they would spend more than 90 percent on their monthly income on rent. Millennials from six other metropolitan area would also spend more than 90 percent of their income on rent. In the Washington-Arlington-Alexandria area, millennials who would pay 110 percent of their income on rent.