Social Security is the closest thing most American households have to a private pension. For a single-earner married couple, the program currently pays roughly $3,120 a month, or $37,440 a year, based on the retired worker’s benefit plus a spousal add-on.
That is guaranteed income, indexed to inflation, and paid until the second spouse dies. Replicating it from a personal portfolio takes a surprisingly large amount of money, and the exact amount depends on what the portfolio holds.
The question worth answering is what size portfolio would be required to replicate that benefit. Bureau of Labor Statistics data shows the average U.S. household spent $78,535 in 2024, so the average Social Security benefit covers less than half of typical outlays.
The question is what size portfolio it would take to produce that same monthly check on its own. That framing sorts households into two groups: those with enough savings to replace Social Security, and those for whom the program does work that private wealth cannot.
The Portfolio Math at Today’s Rates
Start with the classic 4% safe withdrawal rule, designed to fund a 30-year retirement from a mix of stocks and bonds. At a 4% withdrawal rate, generating the average annual benefit requires a portfolio of $936,000. That is the benchmark most retirement calculators produce, and it is roughly what a couple would need in an IRA or 401(k) to match the average Social Security check without touching principal in a normal market.
Interest rates have changed the picture for anyone who wants to skip market risk and live off coupon payments. The 10-year Treasury yield closed July 2026 at 4.75%, the highest reading in a 12-month window that averaged 4.265%. Matching the average annual benefit at that coupon takes about $788,000 in 10-year notes. Stretch out to the 30-year, currently at 5.23%, and the required principal drops to roughly $716,000.
Now do the same math with a bank CD. The FDIC national average 12-month CD rate is 1.68%. Replacing the same annual income out of average CDs would require roughly $2.23 million in principal. The gap between the Treasury number and the CD number is the cost of not shopping for yield.
Why the Real Number Is Higher
Those figures understate what a retiree actually needs because Social Security adjusts for inflation every year. The 2026 cost-of-living adjustment was 2.8%. Core PCE, the Fed’s preferred inflation gauge, has climbed from 126.71 in August 2025 to 130.27 in June 2026, so the purchasing power protection is not theoretical.
A fixed Treasury coupon pays the same dollar amount every year until maturity. If inflation continues to run at recent rates, the real value of that coupon shrinks steadily. Matching an inflation-adjusted benefit on a fixed-income portfolio therefore requires either TIPS, a bond ladder that gets reinvested at future rates, or a larger initial balance to absorb the erosion. That is why the 4% rule uses a diversified stock-and-bond mix rather than a pure bond yield.
What the Gap Looks Like in Practice
Federal Reserve data on household finances puts these portfolio targets into some perspective. The personal savings rate has dropped from 6.2% in the first quarter of 2024 to 2.8% in the second quarter of 2026, while per capita disposable income sits at $68,958. Building a seven-figure balance out of a low single-digit savings rate is no easy task, and that is exactly why Social Security ends up carrying so much of the load.
In the second quarter alone, the program paid out $1.65 trillion, or roughly one third of all federal transfer receipts. The numbers all point the same way. To match the average couple’s Social Security check, a household needs a substantial private portfolio, and the exact size of that target shifts depending on whether the money is parked in long Treasuries, drawn down from a balanced portfolio under the 4% rule, or sitting in average bank CDs.
Households with balances well below those benchmarks are effectively dependent on the program continuing to pay as scheduled, while households above them have simply replicated in the market what Social Security delivers automatically.
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