Vermont Senator Bernie Sanders’ Social Security Expansion Act, reintroduced in February 2025 as S. 770 with ten Senate Democratic co-sponsors, would raise the average beneficiary’s annual payment by about $2,400 by rewriting the formula behind monthly checks and taxing wages above $250,000 to cover the cost. Eighteen months later, the bill remains parked in the Senate Finance Committee without a hearing or a vote, while its House companion, H.R. 1700, sits untouched too. The funding design carries a built-in gap: the payroll tax already reaches every dollar of wages up to $184,500 in 2026, so the bill’s $250,000 threshold would leave a stretch of high earnings untaxed until a later phase-in narrows the difference.
A Formula Rewrite Behind the $2,400 Figure
The bill’s benefit increase comes from changing the arithmetic Social Security uses to convert a worker’s earnings history into a monthly check, not from an across-the-board raise. Current law already replaces a larger share of a retiree’s lowest-earning years than the years above that threshold; the Social Security Expansion Act raises the percentage applied to that lowest bracket further, which lifts monthly payments most for people who spent decades in lower-wage work such as home health aides or retail clerks. Sanders’ office, joined by co-sponsors Elizabeth Warren, Jeff Merkley and Peter Welch, estimates the combined formula change would add about $2,400 a year to the average beneficiary’s check.
Three additional provisions sit inside the same bill text. It creates a new minimum benefit tied to the federal poverty line for a worker with 30 years of covered earnings, combines the separate Old-Age and Survivors and Disability Insurance trust funds into a single Social Security Trust Fund, and switches the annual cost-of-living adjustment from the wage-earner price index to the Consumer Price Index for the Elderly, a Bureau of Labor Statistics measure weighted toward how retirees actually spend on housing and health care. None of the three take effect unless the underlying bill passes; all three are unenacted text sitting in the same Finance Committee referral as the benefit formula change.
For scale, the Social Security Administration’s 2026 cost-of-living adjustment fact sheet lists the average retired-worker benefit at $2,071 a month, or about $24,852 a year, after the 2.8 percent COLA that took effect in January. An additional $200 a month under S. 770 would represent close to a 10 percent increase over that baseline, concentrated most heavily among retirees whose lifetime earnings put them in the bottom half of the wage distribution the new formula favors.
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A Gap Between the 2026 Cap and the New $250,000 Line
The bill pays for the higher formula by extending the Social Security payroll tax beyond its usual annual ceiling. That ceiling, officially the taxable maximum, is set at $184,500 for 2026, meaning every dollar an employee earns above that amount currently owes no Social Security payroll tax at all. Under S. 770, a new tax would apply only to wages above $250,000, phased in starting in 2028 and reaching full application by 2032, according to Sanders’ office summary of the legislation.
That design leaves a gap in the middle of the wage scale: income between the current $184,500 cap and the bill’s $250,000 threshold would remain outside the payroll tax under S. 770, just as it is under existing law, unless the ordinary cap eventually climbs high enough through wage-indexed growth to close the difference on its own. Above $250,000, the new tax would not apply all at once; the taxable share of those earnings would rise in steps between 2028 and 2032. The result is a funding stream that reaches its full size only in the phase-in’s final year, even though the formula changes it is meant to finance could begin sooner.
Raising a second, higher threshold rather than simply lifting the existing cap is not how Social Security financing has always worked. The 1983 amendments were built around taxing 90 percent of national wages, and the program’s own actuaries have documented that share slipping well below that mark in the decades since, as pay for the highest earners grew faster than the wage base’s annual index. S. 770 responds to that drift with a separate, higher line instead of one continuous, gradually rising ceiling, which is why the bill produces a doughnut hole in the wage scale rather than a smooth extension of the existing tax.
Eleven Co-Sponsors, No Committee Vote in 18 Months
Ten additional senators joined Sanders when the bill was introduced on Feb. 27, 2025: Warren, Merkley, Welch, Alex Padilla, Tina Smith, Chris Van Hollen, Edward Markey, Cory Booker, Kirsten Gillibrand and Sheldon Whitehouse. All eleven caucus with Senate Democrats, and no Republican has signed on as a co-sponsor. The bill was read twice on introduction and referred to the Senate Finance Committee the same day; as of Aug. 29, 2026, the committee’s public record shows no hearing, markup or further action tied to S. 770.
A companion measure, H.R. 1700, was introduced the same week by Oregon Representative Val Hoyle and 19 co-sponsors, then referred to the House Ways and Means Committee along with the Education and Workforce and Transportation and Infrastructure committees. It has drawn the identical response: no floor action, no markup, and no Republican co-sponsors in either chamber. S. 770 is one of several Social Security financing proposals now pending before Congress, including Republican-authored bills that address the program’s finances through a higher retirement age or slower benefit growth instead of new payroll taxes on high earners.
Nothing in the bill changes a current beneficiary’s check while it sits in committee; the formula rewrite, the minimum benefit, the trust fund merger and the payroll tax expansion all require enactment before any of the four provisions take effect. The unresolved question is timing rather than intent: even a fast path to passage would not fully fund the promised $2,400 average increase until the tax on wages above $250,000 finishes its 2032 phase-in, leaving a multi-year stretch in which the benefit formula could be more generous than the revenue built to support it. That mismatch, not the size of the tax increase itself, is what a Senate Finance Committee markup would have to resolve before S. 770 could move toward a floor vote.
This article was researched and drafted with the assistance of artificial intelligence.
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