The affordable housing challenge plagues cities across India. Although city administrations have framed various strategies to tackle the issue, weak implementation, flawed policies, and an inherent lack of capacity to find long-term solutions have allowed slums to proliferate as an alternative. This paper examines the affordable housing issue in Greater Mumbai. Since affordability is not absolute but relative to the development stage and income distribution level, this paper presents a city-specific operational definition of affordable housing for Mumbai. It also proposes policy reforms, including shifting the planning focus from municipal limits to the larger metropolitan expanse.