This chapter discusses theories of person-environment interactions and how they relate to where older adults live. It describes models of competence/environmental press and congruence and how they influence decisions about living arrangements. Options discussed include aging in place with home modifications, adult day care, congregate housing, assisted living, and nursing homes. Special care units are designed to provide extra support for those with cognitive impairments. The goal is finding the best fit between an individual's abilities and the demands of their environment.