1. Short title; table of contents (a) Short title This Act may be cited as the Social Security Expansion Act . (b) Table of contents The table of contents of this Act is as follows: Sec. 1. Short title; table of contents. Sec. 2. Across-the-board benefit increase. Sec. 3. Computation of cost-of-living increases. Sec. 4. Increase in minimum benefit for lifetime low earners based on years in the workforce. Sec. 5. Extended benefit eligibility for children who are full-time students. Sec. 6. Payroll tax on remuneration up to contribution and benefit base and more than $250,000. Sec. 7. Tax on net earnings from self-employment up to contribution and benefit base and more than $250,000. Sec. 8. Tax on investment gain. Sec. 9. Social Security Trust Fund established. 2. Across-the-board benefit increase (a) In general Section 215(a)(1)(B) of the Social Security Act ( 42 U.S.C. 415(a)(1)(B) ) is amended— (1) by redesignating clause (iii) as clause (iv); and (2) by inserting after clause (ii) the following new clause: (iii) For individuals who initially become eligible for old-age or disability insurance benefits, or who die (before becoming eligible for such benefits) in any calendar year after 2024, each of the amounts determined under clause (ii) of this subparagraph for purposes of subparagraph (A)(i) shall be increased by— (I) for calendar year 2025, 1 percent; (II) for each of calendar years 2026 through 2038, the percent determined under this clause for the preceding year increased by 1 percentage point