The primary purpose of this book is to investigate demographic and social aspects of aging in nonmetropolitan (nonmetro) areas of the United States (US) in the twenty- fi rst century. Demographic aging refers to the aging of a population whereby the population itself is growing older, not to individual-level aging. Population aging is among the most important worldwide trends in the twentieth and twenty- fi rst centuries, and the trend is occurring more rapidly in rural than urban areas of the US. Rural areas have a disproportionate concentration of older people, with 15% of the nonmetro compared to 12.0% of the metropolitan (metro) population in the 65 years of age and older age group (US Census Bureau 2009 ) . Moreover, within the nonmetro population, the more rural and sparsely populated an area is, the older is its population (Glasgow and Brown 2012 ) . The older age structure in rural and nonmetro areas of the US is similar to other more developed countries. For example, Keating ( 2008 ) , studying rural aging in Canada and the United Kingdom (UK), and Lowe and Speakman ( 2006 ) , focusing on aging in rural England, report that the rural population is aging more rapidly than the urban population in those countries as well. The majority of residents of the US, both young and old, live in cities and suburbs; it is simply that older people form a higher percentage of the country’s nonmetro than metro population (US Census Bureau 2009 ) .