Endowed with proceeds from transactions involving nonprofit healthcare assets, health legacy foundations (HLFs) embody tremendous potential to improve health and healthcare in communities across the nation. This dissertation represents the culmination of a systematic search for HLFs, provides community-level analyses of needs where HLFs are established, and describes how HLFs articulate their intent to pursue a charitable health purpose. The first phase of this research entailed the development of a new, comprehensive database of HLFs, which includes 306 foundations in forty-three states; aggregate HLF assets in 2010 totaled more than $26 billion. The next phase of this study examined health determinants in communities where HLFs have been formed from the sale of local nonprofit hospitals. Compared to non-HLF counties, HLF counties had significantly higher proportions of racial minorities and multiple socioeconomic indicators that render them more vulnerable to health disparities and poor health. The final phase of this research explored the charitable health intent of HLFs formed from hospitals as revealed through their self-defined missions. Although the majority of HLFs adopted an explicit health-related purpose, most depicted health in vague terms. Broadly construed mission statements allow grantmakers the freedom to choose the combination of services and beneficiaries that maximizes utility for their communities. While this flexibility is important for HLFs to address broad health determinants and respond to changing community needs, careful public oversight is critical to ensure that nonprofit healthcare proceeds are strategically redeployed.