This paper looks at alternative rental assistance programs that fall somewhere between HCVs and emergency assistance, a program that could target families with housing instability whose incomes are very low, but not extremely low. This would allow HCVs to serve extremely low income households, but offer alternative to waiting for emergency assistance. The paper begins with an overview of federal and local rental assistance programs and their incapacity to address the growing need for affordable housing. Then, it reviews the existing literature on alternative forms of rental assistance. Finally, it outlines the recommended components for a demonstration to rigorously test the impacts of one alternative assistance program: a flat, shallow subsidy. This paper is sponsored by the What Works Collaborative, a foundation-supported partnership that conducts timely research and analysis to help inform the implementation of an evidence-based housing and urban policy agenda. The What Works Collaborative has funded a handful of incubator projects that complete the first steps toward larger-scale research projects that can be funded in the future. The goal of this incubator project is to outline a proposed demonstration to test alternative rental assistance programs to help families afford housing and decrease residential instability.