Social Security Funding Shortfall: Causes, Gap Size, and Fixes

The Social Security funding shortfall has a specific deadline attached to it: the retirement and survivors trust fund is projected to run out of reserves in 2033, at which point incoming payroll taxes would cover only about 77 percent of scheduled benefits. Combining the retirement fund with the smaller disability fund pushes the date to 2034 and lifts the payable share to 81 percent, but the law keeps the two funds separate, so the 2033 date is the one that matters for retirees. Both figures come from the program’s own Board of Trustees in its 2025 annual report.¹

Why the Money Is Running Short

Social Security was built as a pay-as-you-go system. Today’s workers fund today’s retirees through payroll taxes, and the arithmetic depends on having enough workers per beneficiary to make the numbers work. In 1950, roughly 16.5 workers paid in for every person collecting benefits.² By 1960 it was about 5 to 1. By the mid-1970s, closer to 3 to 1.

The current ratio is about 2.7 workers per beneficiary, and the Trustees project it will slip to 2.6 in 2026.³ Two forces produced that decline. People live longer than they did when the program launched, so each retiree collects benefits for more years. Birth rates have fallen, so fewer workers enter the labor force to replace each retiring cohort. The Baby Boom generation’s retirement compressed both trends into one period.

At 2.7 workers per retiree, the payroll taxes coming in cannot cover the full scheduled benefits going out at current rates. The program has been drawing down its reserves every year to make up the difference. Those reserves peaked at roughly $2.9 trillion and are now depleting steadily.

How the Funding Works

Payroll taxes under the Federal Insurance Contributions Act supply most of the program’s revenue. Employees and employers each pay 6.2 percent of wages, for a combined 12.4 percent that funds retirement, survivor, and disability benefits.⁴ Self-employed workers pay the full 12.4 percent themselves.⁵

The tax only applies up to an annual earnings cap. For 2026 that cap is $184,500, and every dollar earned above it is exempt.⁶ The cap adjusts each year with the national average wage index, but because wages at the top of the income distribution have grown faster than average wages for decades, a larger share of total earnings now sits above the cap and escapes the tax. That quietly shrinks the tax base.

Revenue flows into two accounts created under 42 U.S.C. §401: the Old-Age and Survivors Insurance Trust Fund and the Disability Insurance Trust Fund.⁷ Surpluses are invested in special-issue U.S. Treasury securities that pay interest back into the funds. The disability fund is currently in strong shape and is projected to stay solvent through at least 2099.¹ The retirement fund is the one facing depletion, and the two cannot merge without an act of Congress.

What Happens If Congress Does Nothing

Federal law ties Social Security’s spending power directly to its trust fund balances. Under 42 U.S.C. §401, retirement and survivor benefits “shall be made only from” the OASI fund.⁷ The program has no standing authority to tap general tax revenue or borrow from the Treasury once reserves hit zero.

Depletion would not stop checks entirely. Payroll taxes would keep flowing in every pay period, but they would only cover 77 percent of scheduled benefits starting in 2033.¹ A retiree receiving $2,000 a month would see roughly $1,540 instead, with no phase-in beyond whatever legislative debate happens beforehand.

The Social Security Administration has never had to impose across-the-board cuts of this kind, and the operational details are untested. Whether the agency would reduce every payment by the same percentage, delay checks, or take some other approach is not settled. Congress has always intervened before a depletion event, most recently in 1983, when reforms passed only months before the fund would have run dry.

The Size of the Gap

The 2025 Trustees Report puts the 75-year unfunded obligation for the combined program at $25.1 trillion in present-value terms.⁸ The actuarial deficit stands at 3.82 percent of taxable payroll. In practical terms, closing the gap entirely through a payroll tax hike would require raising the combined rate from 12.4 percent to about 16.2 percent. Closing it entirely through benefit cuts would require reducing scheduled benefits by roughly 24 percent for all current and future beneficiaries. Neither extreme is politically realistic on its own, which is why most serious proposals combine revenue increases with benefit adjustments phased in over time.

The 2025 Fairness Act Moved the Date Up

Signed into law on January 5, 2025, the Social Security Fairness Act repealed the Windfall Elimination Provision and the Government Pension Offset. Those rules had reduced Social Security benefits for roughly 2.8 million people who earned pensions from jobs not covered by Social Security, such as many state and local government positions.⁹

The Congressional Budget Office estimated the repeal would add about $196 billion in benefit payments over ten years. The 2025 Trustees Report identified the Fairness Act as the primary reason the combined depletion date moved up by a year, from 2035 to 2034.¹

Fixes on the Revenue Side

Raising or Eliminating the Payroll Tax Cap

The most frequently discussed revenue option is subjecting more earnings to the payroll tax. Eliminating the cap entirely while crediting the higher earnings toward future benefits would raise an estimated $3.2 trillion over a decade. Applying the tax to wages above $250,000 while leaving a gap between the current cap and that threshold would raise roughly $2.7 trillion. The Social Security Enhancement and Protection Act of 2025, introduced in Congress, takes the phase-out approach and would eliminate the cap entirely by 2035.¹⁰

Raising the Payroll Tax Rate

The same bill proposes gradually raising each side’s contribution from 6.2 percent to 6.5 percent over six years, lifting the combined rate from 12.4 to 13 percent.¹⁰ An incremental increase is less disruptive than a sudden jump but also closes less of the gap on its own.

Fixes on the Benefit Side

Raising the Full Retirement Age

The most debated benefit-side option is pushing the full retirement age beyond 67, which itself is not fully phased in until people born in 1960 or later claim benefits. Raising the retirement age functions as a benefit cut: waiting longer means either collecting reduced benefits earlier or receiving the same monthly check for fewer years. Some versions of the idea pair the increase with protections for lower-income workers, whose life expectancies have not risen as much as those of higher earners.

Changing the Cost-of-Living Formula

Annual cost-of-living adjustments are currently calculated using the Consumer Price Index for Urban Wage Earners and Clerical Workers, known as CPI-W. Some proposals would switch to a slower-growing index to reduce annual increases. Others favor switching to CPI-E, an experimental index that tracks spending by Americans 62 and older and tends to grow slightly faster.¹¹ Switching to CPI-E would raise benefits modestly each year but would pull the insolvency date closer by an estimated three to five years. Moving to a slower index would extend solvency but reduce purchasing power for retirees over time.

The Cost of Waiting

Every year Congress delays, the eventual fix has to be sharper. Options narrow, and the size of the tax increase or benefit cut needed to restore long-term balance grows. The 1983 reforms passed just months before the trust fund would have run out. Whether lawmakers act with more lead time this round or repeat the last-minute pattern will decide whether the adjustment lands gradually or abruptly on the roughly 70 million Americans who depend on these benefits.

1
Social Security Administration. A Summary of the 2025 Annual Reports
2
Social Security Administration. Ratio of Covered Workers to Beneficiaries
3
Social Security Administration. Fast Facts and Figures About Social Security, 2025
4
Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates
5
Office of the Law Revision Counsel. 26 U.S.C. Chapter 2 – Tax on Self-Employment Income
6
Social Security Administration. Contribution and Benefit Base
7
Office of the Law Revision Counsel. 42 USC 401 – Trust Funds
8
Social Security Administration. The 2025 Annual Report of the Board of Trustees
9
Social Security Administration. Social Security Fairness Act: Windfall Elimination Provision and Government Pension Offset Update
10
Congress.gov. H.R.3517 – 119th Congress (2025-2026): Social Security Enhancement and Protection Act of 2025
11
Social Security Administration. Social Security Cost-of-Living Adjustments and the Consumer Price Index