|This memo addresses the question of how local governments can enforce housing codes to enable low- income tenants to live in safe and healthy housing. It reviews the market for low-cost rental housing and provides an outline of the “dynamics” of this market. The memo identifies three models in use today for enforcing housing codes: the “deterrence” model, the strategic code enforcement model and a meta-regulation model. The memo uses regulatory theory to analyze the interaction between each of these models and the dynamics of the low-cost rental market for housing. This analysis reveals that local governments often enforce housing codes in ways that reinforce practices that result in low-income tenants living in unsafe and unhealthy housing. It also identifies the potential for local governments to use enforcement to influence the dynamics of the low-cost market for rental housing to enable low-income tenants to live safety and healthy housing. These enforcement approaches require collaboration between local and state governments, the federal government and community organizations.