EXECUTIVE SUMMARY The Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (Public Law 104-193) directs the Social Security Administration (SSA) to report annually to the President and to the Congress on the status of the Supplemental Security Income (SSI) program. Projections of program recipients and costs through at least 25 years are required elements of these reports. This report is the 21st of such reports. Highlights of the SSI Program • The SSI program is a nationwide Federal assistance program administered by SSA that guarantees a minimum level of income for aged, blind, or disabled individuals. It acts as a safety net for individuals who have limited resources and little or no Social Security or other income. Individual States have the option to supplement Federal payments. • In January 2017, 8.12 million individuals received monthly Federal SSI payments averaging $526, a decrease of 30 thousand recipients from the 8.15 million recipients with an average payment of $526 in January 2016. [D] • Federal expenditures for cash payments under the SSI program during calendar year 2016 decreased 0.4 percent to $54.6 billion, while the funds made available to administer the SSI program in fiscal year 2016 decreased 0.5 percent to $4.3 billion. In 2015, the corresponding program and administrative expenditures were $54.8 billion and $4.3 billion, respectively. Major Findings of the Report • By 2041, the end of the 25-year projection period, we estimate that the Federal SSI recipient population will reach 9.0 million. The projected growth in the SSI program over the 25-year period is largely due to the overall growth in the U.S. population, though the growth in the SSI recipient population is projected to be somewhat slower than the growth in the U.S. population. • As a percentage of the total U.S. population, the number of Federal SSI recipients decreased slightly from 2.49 percent in 2015 to 2.45 percent in 2016. We project this percentage to gradually decline throughout the 25-year projection period, reaching 2.26 percent of the population in 2041. • We estimate that Federal expenditures for SSI payments in calendar year 2017 will decrease by $0.3 billion to $54.3 billion, a decrease of 0.5 percent from 2016 levels. • In dollars adjusted by the Consumer Price Index to 2017 levels, we project that Federal expenditures for SSI payments will increase to $61.5 billion in 2041, a real increase of 0.4 percent per year. • Federal SSI expenditures expressed as a percentage of the Gross Domestic Product (GDP) were 0.29 percent in 2016. We project that expenditures as a percentage of GDP will decrease to 0.28 percent of GDP in 2017, and continue to decline thereafter to 0.20 percent of GDP by 2041.