The Supplemental Security Income (SSI) program assists people who have a disability or who are over age 65 and have low incomes and few assets. But SSI benefits are limited, and the base federal benefit has not been increased since the program began. This fact sheet estimates the antipoverty impacts of four SSI program changes proposed in the Supplemental Security Income Restoration Act of 2021. We find that, taken together, these four provisions would reduce the number of people in poverty by 3.3 million, including 1.2 million people over age 65, 1.2 million adults with disabilities, 558,000 adults who live with an SSI recipient, and 402,000 children. Further, the provisions would more than halve the percentage of SSI recipients in poverty, from 35.7 percent to 16.1 percent.