This article reexamines the thesis that marriage is becoming deinstitutionalized. It first reviews relevant theoretical literature on social institutions, including the “new institutionalism” and the work of Bourdieu on cultural capital. It addresses the great social class differences that have emerged in American family life over the past few decades and their implications for the deinstitutionalization thesis. It then evaluates the thesis, with these conclusions: What has happened in recent years to the place of marriage in the broader field of intimate partnerships is consistent with the deinstitutionalization thesis, although primarily among the non‐college‐educated. In contrast, marriage still plays a central role in the field of intimate partnerships among the college‐educated. Moreover, the behavior of partners within marriage has not change enough to conclude the deinstitutionalization has occurred. The article also examines related claims about marriage and individualism, the concept of capstone marriage, and same‐sex marriage.