Social Security (comprising Old-Age and Survivors Insurance (OASI) and Disability Insurance (DI)) is the largest single program in the federal government’s budget. In 2010, annual outlays for the program exceeded annual revenues (excluding interest) credited to the combined trust funds. A gap between those amounts has persisted since then, and in fiscal year 2015 outlays exceeded tax revenues by almost 9 percent. As the baby-boom generation retires over the next 10 years, the Congressional Budget Office (CBO) projects, the gap will widen between amounts credited to the trust funds and payments to beneficiaries. This book considers 36 policy options that are among those commonly proposed by policymakers and analysts as a means of restoring financial security to the Social Security program. Furthermore, this book presents additional information about CBO’s long-term projections for Social Security in the form of 15 exhibits that illustrate the program’s finances and the distribution of benefits paid to and payroll taxes collected from various groups of people.