Part of the Department of Labor's (DOL) mission is to promote the retirement security of America’s workers, a goal that has become increasingly challenging. One tool for assessing the adequacy of retirement income is the replacement rate. However, recommendations for the replacement rate that a household should target vary widely, in part because of the diverse underlying assumptions used to develop the rates. This book examines whether and how spending patterns vary by age; key factors used to develop target replacement rates; and the usefulness of information on such rates provided by DOL.