<p>In urban planning circles, the phrase “land banking” is emerging with increased frequency, in discussions on housing affordability and urban environmental sustainability. Although land banking has been around for over fifty years, it is only recently that the concept has grown in popularity and come to light as a useful planning tool in these two broad fields. The recent growth of this tool for divergent purposes suggests a need to define its use in planning practice. This research provides empirical evidence of existing land banking efforts and serves as a starting point for understanding how planners might model this into practice. This research examines the “why” of land banking in four cities in Missouri: Kansas City, St. Joseph, St. Louis, and Springfield. This is accomplished through qualitative research with land banking experts and advocates at each case site location. It finds that each of the four municipalities has a different overarching vision for the utilization of land banking, including the creation of affordable housing, addressing social justice concerns, and the rehabilitation of aging housing stock to stabilize neighborhoods. It also finds that a lack of clarity or conflicting purposes for the land bank are common and somewhat problematic to each case site. It is hoped that this research will assist communities interested in understanding <i>why</i> land banking is a tool worth pursuing.</p>