Purpose of the Study: The effects of the physical-spatial-technical environment on aging well have been overlooked both conceptually and empirically. In the spirit of M. Powell Lawton's seminal work on aging and environment, this article attempts to rectify this situation by suggesting a new model of how older people interact with their environment. Design and Methods: Goals of the paper include (a) integration of the essential elements of the ecology and aging literature, particularly in regard to Lawton's research, (b) development of connections between traditional theories of ecology of aging and life span developmental models of aging well, (c) acknowledgment of the pronounced historical and cohort-related changes affecting the interactions of older people with their environment, and (d) discussion of the implications of this analysis for concepts and theories of aging well. Results: The model builds on a pair of concepts: environment as related to agency and belonging, founded in motivational psychology, and developmental science. Implications: After describing the model's key components, we discuss its heuristic potential in four propositions for future gerontological research and identify implications of the model for future empirical research.