This report presents a review of the major U.S. federal and state means-tested programs, including a review of how they operate, common features, and rules governing eligibility. The review covers the nature of the target recipient population, the nature of the benefits (cash or in-kind), whether the program is an entitlement, as well as financial and nonfinancial eligibility rules and benefit determination. Each of the features is compared to that of the Supplemental Security Income (SSI) program. The review reveals that SSI has many common features with other transfer programs, and that many other differences follow naturally from its particular goals and aims. However, large differences between SSI and other programs exist in financial eligibility rules. The current upper income limits for SSI are in the approximate range of 75 to 80 percent of the poverty line for single and married-couple recipients, respectively, below the 100- to 130-percent of the poverty line income limits for Supplemental Nutrition Assistance Program (SNAP), the 130- to 185-percent limits for school food programs, the 185 percent limits for Women, Infants, and Children (WIC), the 138-percent limits for Medicaid, and the 100-percent limits for Workforce Innovation and Opportunity Act (WIOA). Another significant difference is in resource and asset tests in SSI, which have been held constant in nominal dollars since 1989 and hence have been becoming more restrictive in real terms over time. Most other transfer programs have been moving in the opposite direction, reducing the restrictiveness of their asset tests, exempting additional items from countable assets, and in many cases eliminating asset tests entirely.