The Fostering Connections to Success and Increasing Adoptions Act of 2008 will soon allow states to claim federal reimbursement for the costs of caring for and supervising Title IV-E eligible foster youth until their 21st birthday. This issue brief provides some preliminary estimates of what the potential costs to government and benefits to young people will be if states extend foster care to age 21. We focus on the increase in postsecondary educational attainment associated with allowing foster youth to remain in care until they are 21 years old and the resulting increase in lifetime earnings associated with postsecondary education. Our best estimate is that lifetime earnings would increase an average of two dollars for every dollar spent on keeping foster youth in care beyond age 18.