In September 2015, Family Housing Resources, Inc. contracted with the University of Arizona to conduct a gap analysis of affordable housing in Pima County. The scope of work included a review of existing and planned affordable housing, an assessment of future demand, and an analysis of strategies and best practices for increasing affordable housing. To complete the scope we analyzed public and private data sets, produced analytical maps, conducted surveys and interviews with key stakeholders and housing providers, and gathered information on best practices from around the country. In this study, “affordable housing” refers to housing that costs lower-income households no more than 30% of their income to rent or own. “Lower income” households are defined as those earning less than 80% of the county median household income. We define an affordable housing gap as any significant departure from what a reasonable person might consider a desirable situation. Examples would include situations where lower-income households are paying more than they can afford for housing, where the housing they can afford is too far from where they work, or where affordable housing units are too small to meet their needs. There can of course be various views on the gaps that are important, so we look at the issue from several perspectives, hoping to address a range of concerns.