This report examines health services use and population dynamics among the aging homeless population in New York City. Evidence suggests that adverse health outcomes lead to homelessness, and the conditions related to homelessness lead to or exacerbate a range of health problems (Hwang, 2001). In addition, the barriers to accessing preventative and primary care while homeless lead to receipt of healthcare only when morbidities are more acute, (Reid, Vittinghoff, & Kushel, 2008; Kushel, Gupta, Gee, & Haas, 2006; Lim, Andersen, Leake, Cunningham, & Gelberg, 2002) meaning that there is a disproportionate use of inpatient hospitalization and other costly medical and behavioral health services among persons experiencing homelessness (Doran et al., 2013; Hwang, Weaver, Aubry, & Hoch, 2011; Kushel, Perry, Bangsberg, Clark, & Moss, 2002; Salit, Kuhm & Hartz, 1998). As a result, homelessness is expensive for healthcare systems and for society as a whole (Latimer et al., 2017; Flaming, Burns, & Matsunaga, 2009; Culhane, 2008). Given this, interest in using healthcare systems as a platform to address homelessness has grown in recent years. Strategies include efforts to identify homeless

patients in healthcare settings in order to link them with housing and social services (Garg, Toy, Tripodis,

Silverstein, & Freeman, 2015; Gottlieb, Hessler, Long, Amaya, & Adler, 2014); the creation of accountable care organizations that seek to coordinate healthcare and social services for persons experiencing housing instability (Mahadevan & Houston, 2015); and the development of new financing mechanisms geared towards using healthcare dollars to support housing stability (Burt, Wilkins, & Locke, 2014).