Lawmakers do have one near-term lever: combining the OASI trust fund with the Disability Insurance trust fund. That move could push the combined depletion date back to the third quarter of 2034, at which point 83% of benefits would remain payable. But that option only buys time — it does not resolve the underlying funding gap.
Social Security is primarily financed through payroll taxes, with trust funds holding previous surpluses plus interest invested in special-issue U.S. Treasury securities. The Social Security Administration describes these instruments as «just as safe as U.S. savings bonds or other financial instruments of the federal government.» The government has always reimbursed the program with interest — but without legislative action, long-term securities would need to be redeemed before maturity.
A $600 billion annual shortfall on top of a $46.5 trillion national debt
The scale of the funding gap is stark. Social Security’s annual shortfall is projected to reach $600 billion in 2033 and grow to roughly $700 billion by 2036, according to the Mercatus Center research co-authored by Veronique de Rugy, senior research fellow at the Mercatus Center, and Jason Fichtner, executive director at the LIMRA Retirement Income Institute. That shortfall would land on top of an estimated $2.7 trillion federal deficit and a $46.5 trillion national debt in 2033.
«But at that point, the bond market looks and says, ‘Well, you guys have 12 months to get your act in order; you’re going to be looking for another $600-plus billion a year,’» Fichtner told CNBC. The concern is not just the size of the number — it is the speed at which markets could reprice risk once Congress appears unlikely to act.
The Committee for a Responsible Federal Budget puts the long-term tab even higher. Marc Goldwein, senior vice president at the CRFB, cites $800 trillion in borrowing over the 75-year solvency window in nominal terms, or $180 trillion adjusted for inflation. «Fiscal strain could come earlier than trust fund depletion,» Fichtner warned.
Several early warning signs are already visible, according to the research. Foreign holdings of U.S. Treasurys have declined amid global uncertainty and new tariff policies. Inflation has not yet returned to the Federal Reserve’s 2% target, and longer-maturity rates for Treasury Inflation-Protected Securities suggest markets expect elevated inflation to persist. De Rugy and Fichtner describe recent disruptions to Treasury auctions as a «harbinger of things to come.»
How Social Security is funded
Social Security is primarily financed through payroll taxes paid by workers and employers. When revenues exceed benefit payments, surpluses are invested in special-issue U.S. Treasury securities held in trust funds. The program has run deficits since 2021, drawing down those reserves — a trend the trustees project will continue until the funds are exhausted in the early 2030s.
Mortgage rates at nearly 9%, credit costs surging: the consumer impact of inaction
If Congress were to fund Social Security through general revenue — effectively opening the program to large-scale deficit borrowing — the ripple effects on everyday borrowing costs could be severe. A 4% neutral rate on 10-year Treasury bonds could rise to 6.6%, according to 2025 research from the CRFB. A 30-year fixed-rate mortgage could jump from 6.3% to nearly 9% under that scenario.
