Social Security & Medicare: The $100 Trillion Unfunded Liability
Zach Hill · February 28, 2026
Last Updated: February 2026
The U.S. national debt stands at roughly $40 trillion — a staggering figure that dominates headlines and political debates. But there is an even larger number hiding in plain sight: the federal government's unfunded liabilities, which exceed $100 trillion when you account for the gap between what Social Security and Medicare have promised to pay and what they are projected to collect in revenue.
This is not some abstract accounting exercise. These are real commitments to real people — the retirement checks, hospital bills, and prescription drug coverage that hundreds of millions of Americans are counting on. And the money to pay for it all does not exist yet.
This article explains what unfunded liabilities are, how they dwarf the official national debt, when the trust funds will run out, and what options exist to close the gap.
Key Takeaways
- Total unfunded liabilities for Social Security and Medicare exceed $100 trillion over a 75-year projection window
- The Social Security Trust Fund is projected to be depleted by 2033, after which benefits would be automatically cut by approximately 21%
- Medicare Part A (Hospital Insurance) faces depletion by 2031, triggering automatic payment reductions to hospitals
- These obligations are 3x larger than the official national debt but do not appear on the government's balance sheet
- Every year of inaction makes the problem ~$3-4 trillion worse as the shortfall compounds
- The ratio of workers to retirees has fallen from 5.1:1 in 1960 to 2.7:1 today, and is heading toward 2.1:1 by 2040
What Are Unfunded Liabilities?
An unfunded liability is the difference between what a program has promised to pay in future benefits and the revenue it is expected to collect to pay for those benefits. It is the gap between obligations and resources.
Think of it this way: if you promised to pay someone $1,000 per month for 30 years ($360,000 total), but you only have $200,000 saved and expect to earn another $100,000 in contributions, your unfunded liability is $60,000 — the gap between what you owe and what you have or expect to receive.
For the federal government, unfunded liabilities primarily come from two enormous programs:
- Social Security (OASDI): ~$26.2 trillion in unfunded obligations over 75 years
- Medicare (Parts A, B, D): ~$52.2 trillion in unfunded obligations over 75 years
- Federal employee pensions and other: ~$9.6 trillion
- Other federal commitments: ~$15+ trillion (state Medicaid matches, implicit guarantees, etc.)
Combined, these obligations represent over $103 trillion in promises that lack identified funding — nearly triple the official national debt.
Social Security: The Clock Is Ticking
How Social Security Works
Social Security operates primarily on a "pay-as-you-go" basis. Today's workers pay payroll taxes (12.4% of wages, split between employer and employee) that fund today's retirees. The program does not save or invest contributions for individual workers — it transfers money from current workers to current beneficiaries.
When the program collected more in taxes than it paid in benefits (as it did from 1983 to 2020), the surplus went into the Social Security Trust Fund, which holds special-issue Treasury bonds. These bonds represent IOUs from the rest of the federal government.
The Trust Fund Depletion Timeline
| Trust Fund | Current Balance | Projected Depletion | Benefit Cut After Depletion |
|---|---|---|---|
| Old-Age & Survivors (OASI) | ~$2.6 trillion | 2033 | ~21% automatic cut |
| Disability Insurance (DI) | ~$120 billion | 2098+ | Solvent for foreseeable future |
| Combined OASDI | ~$2.7 trillion | 2034 | ~20% automatic cut |
What "Depletion" Actually Means
When the trust fund is "depleted," Social Security does not go bankrupt or disappear. Payroll taxes will still flow in, covering approximately 79% of promised benefits. But under current law, the Social Security Administration would be required to cut all benefits by roughly 21% across the board — because it can only pay out what it collects.
For the average retiree receiving $1,920 per month, that would mean an immediate reduction to approximately $1,517 per month — a loss of $403 per month or $4,836 per year.
Why Social Security Is Underfunded
- Demographics: The Baby Boom generation (born 1946-1964) is retiring at a rate of ~10,000 per day. There are 67 million beneficiaries today, projected to reach 80+ million by 2035.
- Falling worker-to-retiree ratio: In 1960, 5.1 workers supported each retiree. Today it is 2.7:1. By 2040, it will be approximately 2.1:1.
- Increasing longevity: When Social Security began in 1935, life expectancy at 65 was about 13 additional years. Today it is over 19 years — meaning benefits are paid for 46% longer.
- The taxable wage cap: Only the first $176,100 (2026) in wages is subject to Social Security tax. Earnings above that cap are exempt, and the cap has not kept pace with income concentration at the top.
- Lower birth rates: Fewer workers entering the labor force means a smaller tax base supporting a growing retiree population.
Medicare: An Even Larger Problem
Medicare's Four Parts
| Part | Coverage | FY2026 Cost | Funding Source | Solvency Issue |
|---|---|---|---|---|
| Part A (Hospital Insurance) | Hospital stays, skilled nursing, hospice | ~$380 billion | 2.9% payroll tax | Trust fund depletes ~2031 |
| Part B (Medical Insurance) | Doctor visits, outpatient care, lab tests | ~$390 billion | 25% premiums, 75% general revenue | Cannot technically go "insolvent" — draws from general revenue |
| Part C (Medicare Advantage) | Private insurer alternative to A+B | Included in A+B | Government payments to insurers | Growing faster than traditional Medicare |
| Part D (Prescription Drugs) | Outpatient prescription drug coverage | ~$130 billion | 25% premiums, 75% general revenue | Cannot technically go "insolvent" — draws from general revenue |
Why Medicare Is More Dangerous Than Social Security
While Social Security's shortfall is large ($26 trillion), Medicare's is far larger ($52 trillion) and harder to fix for several reasons:
- Healthcare costs grow faster than wages or GDP: Per-capita healthcare spending has grown at ~5-7% annually for decades, far outpacing the ~3-4% growth in the tax base that funds Medicare
- New treatments and technologies constantly add costs: Unlike Social Security, which pays a defined dollar amount, Medicare's cost depends on the evolving cost of healthcare
- An aging population needs more healthcare: Per-capita Medicare spending for those 85+ is roughly 3x that of those 65-69
- Parts B and D draw from general revenue: These programs cannot technically "run out" because they automatically draw from general tax revenue — but this means their growing costs crowd out all other spending and increase the deficit
Medicare Part A Trust Fund Depletion
The Hospital Insurance trust fund is projected to be depleted by approximately 2031 — even sooner than Social Security. After depletion, Medicare could only pay hospitals approximately 89% of their bills, potentially causing:
- Hospitals reducing services or closing, especially in rural areas
- Longer wait times for procedures
- Providers refusing to accept Medicare patients
- Shifts of costs to private insurance (increasing premiums for working-age Americans)
Why Unfunded Liabilities Are Not on the Balance Sheet
The official national debt of $40 trillion represents money the government has already borrowed. Unfunded liabilities represent money the government has promised to spend but has not yet borrowed. This distinction matters because:
- Government accounting uses "cash basis" — it counts spending when checks are written, not when obligations are incurred
- Private companies would be required to report these liabilities — if a corporation had $100 trillion in unfunded pension and healthcare obligations, it would be on their balance sheet
- The "infinite horizon" unfunded liability is even larger: Looking beyond 75 years to the infinite future, total unfunded liabilities have been estimated at $200+ trillion by some economists
The annual Social Security and Medicare Trustees' Reports provide the authoritative estimates. You can track the current debt on our live debt tracker while these unfunded obligations grow in the background.
The Generational Impact
Unfunded liabilities are fundamentally a generational issue. Current retirees and near-retirees will likely receive their full promised benefits. The burden falls on:
| Generation | Birth Years | Impact |
|---|---|---|
| Silent Generation | 1928-1945 | Will receive full benefits — already retired |
| Baby Boomers | 1946-1964 | Most will receive full or near-full benefits; youngest Boomers may see modest cuts |
| Generation X | 1965-1980 | Face potential 15-25% benefit reductions if no reforms enacted |
| Millennials | 1981-1996 | Face higher taxes, later retirement ages, or significant benefit cuts (20-30%) |
| Generation Z | 1997-2012 | Will bear the heaviest fiscal burden — higher taxes for lower benefits |
| Generation Alpha | 2013+ | Programs may be fundamentally restructured by the time they retire |
Per the CBO, every year of delay makes the eventual fix more painful. If Congress had acted in 2000, a payroll tax increase of ~1.9 percentage points would have kept Social Security solvent for 75 years. Today, the required increase is ~3.4 percentage points — and it grows larger every year.
Reform Options: How to Close the Gap
Social Security Reform Options
| Reform Option | % of Shortfall Closed | Political Feasibility |
|---|---|---|
| Raise payroll tax from 12.4% to 15.8% | 100% | Very difficult — tax increase on all workers |
| Eliminate taxable wage cap entirely | ~70% | Moderate — affects only high earners ($176K+) |
| Raise full retirement age from 67 to 70 | ~30% | Moderate — phased in over decades |
| Reduce benefits by 21% for all beneficiaries | 100% (this is the automatic cut) | Politically unacceptable — would impoverish millions |
| Means-test benefits (reduce for wealthy retirees) | ~10-15% | Moderate — changes program from universal to welfare |
| Change COLA formula to Chained CPI | ~20% | Moderate — results in gradually smaller annual increases |
| Invest trust fund in equities (not just Treasuries) | ~15-25% | Difficult — raises concerns about government stock ownership |
| Combination of above measures | 100% | Most likely path — some of each |
Medicare Reform Options
- Negotiate drug prices: The Inflation Reduction Act (2022) began Medicare drug price negotiation for the first time; expanding this could save $100+ billion over a decade
- Raise the Medicare eligibility age: From 65 to 67 (aligned with Social Security) — saves ~$5 billion annually but shifts costs to employers and individuals
- Increase premiums for higher-income beneficiaries: Already partially in place — expanding income-related adjustments could raise significant revenue
- Shift to premium support (voucher system): Give beneficiaries a fixed dollar amount to purchase private coverage — controversial, could save money or increase costs depending on design
- Reduce provider payment rates: Pay hospitals and doctors less — risks access issues if providers drop Medicare
- Systemic healthcare reform: Address the underlying reasons U.S. healthcare costs 2-3x per capita what other developed nations spend
What Happens If Nothing Is Done?
If Congress takes no action, current law dictates the following cascade of events:
- ~2031: Medicare Part A trust fund depleted. Hospitals automatically receive only ~89% of billed amounts. Rural hospital closures accelerate.
- ~2033: Social Security OASI trust fund depleted. All retirement benefits automatically cut by ~21%. Average monthly benefit drops from $1,920 to ~$1,517.
- Ongoing: Medicare Parts B and D draw increasingly from general revenue, widening the annual deficit and adding to the national debt.
- 2030s-2040s: Interest payments on the growing debt consume an ever-larger share of the budget, creating a fiscal spiral where the government borrows to pay interest on previous borrowing.
- Long term: Without reform, these programs either deliver dramatically reduced benefits or require tax increases of 30-50% — or some combination of both.
Track the current trajectory on our real-time debt clock and explore historical patterns in our debt by year analysis.
How Other Countries Handle It
The U.S. is not alone in facing unfunded retirement and healthcare liabilities, but its approach differs from most peer nations:
- Canada: Reformed its pension system (CPP) in the 1990s with a combination of tax increases, benefit adjustments, and partial pre-funding through equity investments. The CPP Investment Board now manages over $500 billion (CAD).
- Sweden: Implemented "notional defined contribution" accounts that automatically adjust benefits based on life expectancy and economic growth — essentially self-correcting.
- Australia: Requires employers to contribute 12% of wages to mandatory private retirement savings accounts (superannuation), reducing reliance on government pensions.
- Singapore: Central Provident Fund requires 37% combined employer/employee contributions to individual savings accounts used for retirement, healthcare, and housing.
- Japan: Facing even worse demographics than the U.S., Japan has raised retirement ages, reduced benefits, and accepted that healthcare spending for its aging population will consume an increasing share of GDP.
Frequently Asked Questions
Is Social Security going bankrupt?
No. "Bankrupt" implies zero money — Social Security will continue to collect payroll taxes indefinitely. Even after the trust fund is depleted (~2033), incoming taxes will cover approximately 79% of promised benefits. The issue is a ~21% shortfall, not a complete shutdown. Congress will almost certainly act before allowing automatic benefit cuts, though the form of that action is hotly debated.
Will I get my Social Security benefits?
Almost certainly, but they may be modified. If you are currently over 55, the overwhelming political consensus is that your benefits will not be significantly changed. If you are under 40, it is prudent to plan for benefits that may be 15-25% lower than currently promised, a higher retirement age (potentially 68-70), or higher taxes to maintain current benefit levels.
What is the difference between the national debt and unfunded liabilities?
The national debt ($40 trillion) represents money already borrowed — bonds issued and outstanding. Unfunded liabilities ($100+ trillion) represent future promised spending that exceeds projected future revenue. The debt is a legal obligation today; unfunded liabilities are a projected gap that could be closed by changing future benefits, taxes, or both.
Why don't politicians fix this?
Fixing unfunded liabilities requires either raising taxes or cutting benefits — both politically toxic. Social Security and Medicare are called the "third rail" of American politics because touching them can end political careers. The problem is also distant enough (trust fund depletion is years away) that Congress faces little immediate pressure to act. Historical precedent (the 1983 Social Security reform) suggests Congress will act only when depletion is imminent.
Can DOGE or spending cuts fix unfunded liabilities?
No. Unfunded liabilities are a structural problem driven by demographics (more retirees, fewer workers) and healthcare cost growth. Cutting federal waste through DOGE initiatives or other efficiency measures can reduce the annual deficit but cannot close a $100 trillion gap in entitlement programs. Only reforms to Social Security and Medicare themselves — their tax rates, benefit formulas, eligibility ages, or fundamental structure — can address unfunded liabilities.
How much would it cost to fully fund these programs?
To close the 75-year gap today, the government would need to either: (a) immediately increase payroll taxes by roughly 4.4 percentage points (combined Social Security + Medicare), (b) immediately cut benefits by roughly 25%, or (c) deposit approximately $26 trillion into the Social Security trust fund and $52 trillion into Medicare trust funds — which is obviously impossible. The most realistic path involves a combination of modest tax increases, gradual benefit adjustments, and structural reforms phased in over decades.
Related Resources
- US Debt Clock — Real-time national debt, including unfunded liability counters
- Live Debt Tracker — Watch the numbers move in real time
- Where Your Tax Dollars Go — Full budget breakdown including Social Security & Medicare
- Understanding the National Debt — Complete beginner's guide
- Debt-to-GDP Ratio Explained — Why ratios matter more than raw numbers
- US Debt by Year — Historical context from 1790 to today
- Making Sense of Government Spending — Visual spending guide
- Debt Calculator — Model future scenarios
- Inflation Tracker — Track how inflation impacts purchasing power
- Debt Glossary — Key fiscal terms explained
Data sources: Social Security Board of Trustees Annual Report (2025), Medicare Board of Trustees Annual Report (2025), Congressional Budget Office Long-Term Budget Outlook, Government Accountability Office. Updated February 2026.