Strategies to help the one billion people worldwide who live in informal settlements have mainly focused on slum upgrading, sites and services programs, and tenure security. In contrast, there has been less attention on what enables slum dwellers to transition into the formal housing sector, which has the dual benefits of improving service access and escaping social stigma. In this paper the authors investigate residential mobility among slum dwellers in Bhopal, India. Their analysis shows that one in five households succeeds in getting out of a slum settlement, and a major determinant is the household's ability to save on a regular basis. Due to limited outreach of institutional housing finance, most slum dwellers rely solely on household savings for purchasing a house. These findings underscore the urgent need to improve savings instruments for slum dwellers and to downmarket housing finance to reach the poorest residents of rapidly growing cities in developing countries.