There is strong evidence that housing conditions affect population health, but evidence is limited on the extent to which housing with supportive social services can maintain population health and reduce the use of expensive hospital services. We examined a nonprofit, community-based program in Queens, New York, that supplied affordable housing with supportive social services to elderly Medicare beneficiaries. We evaluated whether this program reduced hospital use, including hospital discharges for ambulatory care–sensitive conditions (ACSCs). We compared hospital use among an intervention group residing in six high-rise buildings in two neighborhoods to that among their Medicare counterparts living in the same neighborhoods but in different buildings. We found that hospital discharge rates were 32 percent lower (p < 0.01)., hospital lengths-of-stay one day shorter (p < 0.05), and ACSC rates 30 percent lower among residents in the intervention group (p < 0.01).than among people in the comparison group. This suggests that investments in housing with supportive social services have the potential to reduce hospital use and thereby decrease spending for vulnerable older patients.