Significant demographic changes are transforming the structure of today's American population to include a much larger proportion of older people. Factors such as immigration and changes in marriage, cohabitation, divorce, and childbearing are all affecting the roles of older people and the way in which older people are financially, emotionally, and psychologically supported. These changes also affect the size and composition of the working-age population that provide this support. Through the review of recent literature, the authors examine the implications of these changes and the ways in which they affect age distribution, immigration, increasing longevity, and family change.