The Entitlement Cliff

The single most important fact about the federal budget is that most of it is on autopilot. Roughly 70% of all federal spending is “mandatory” — meaning it is authorized by permanent law and does not require an annual vote from Congress. Social Security checks go out automatically based on eligibility formulas written decades ago. Medicare reimburses hospitals based on fee schedules set by statute. Medicaid pays state claims based on a matching formula established in 1965. These programs do not compete for funding in the annual budget process. They simply spend whatever the formulas dictate, and the Treasury borrows the difference.

In 2000, federal transfer payments — the broadest measure of benefit payments to individuals — totaled $1.03 trillion. By 2010, they had more than doubled to $2.33 trillion, partly due to the financial crisis. By 2024, they reached $4.40 trillion. The growth has been relentless: transfers increased every single year except 2021 (a technical decline as pandemic-era supplemental payments wound down) and 2022. They have grown at an average rate of 6.2% per year — roughly double the rate of GDP growth — for a quarter century.

Within transfers, federal social insurance benefits are the largest and fastest-growing component. This category — which includes Social Security retirement and disability, Medicare Parts A through D, and military retirement — grew from $655 billion in 2000 to $2.61 trillion in 2024, a fourfold increase. Social Security alone pays out roughly $1.4 trillion per year to 67 million beneficiaries. Medicare pays $900 billion in hospital and physician costs for 65 million enrollees. Together, these two programs account for more than half of all transfer spending and roughly one-third of the entire federal budget.

The remaining transfers include Medicaid ($600 billion), supplemental nutrition assistance ($120 billion), veterans’ benefits ($280 billion), unemployment insurance ($30 billion in normal years), and a patchwork of smaller programs. Every one of these programs has its own growth trajectory, its own political constituency, and its own legal mandate. Cutting any of them requires an affirmative act of Congress, signed by the president. In the 25 years since 2000, no such cut has occurred to any major entitlement program. The only major change — the addition of Medicare Part D (prescription drugs) in 2003 — made the system more expensive, not less.

The growth of entitlement spending is not mysterious. It is driven by a single, predictable, and unstoppable force: 73 million Baby Boomers are retiring. The oldest Boomers (born 1946) turned 65 in 2011. The youngest (born 1964) will turn 65 in 2029. Between those dates, the number of Americans aged 65 and older will grow from 40 million to an estimated 73 million — an 83% increase. Every one of those new retirees is entitled to Social Security benefits (averaging $1,907 per month in 2024) and Medicare coverage (averaging $15,000 per year in per-capita spending).

The math is unforgiving. In 2000, there were 3.4 workers for every Social Security beneficiary. By 2024, that ratio had fallen to 2.7 workers per beneficiary. By 2035, it will fall to approximately 2.3. Each worker’s payroll taxes must support a larger share of each retiree’s benefits. Meanwhile, retirees are living longer: life expectancy at 65 has increased from 15 years (when Social Security was created in 1935) to 20 years today. A worker retiring at 65 can expect to collect benefits for two decades — compared to the five years the program’s designers assumed.

The Social Security Board of Trustees projects that the Old-Age and Survivors Insurance (OASI) Trust Fund will be exhausted by 2033. After that, incoming payroll taxes will cover only 77% of scheduled benefits. Without congressional action, benefits would be automatically cut by 23% — reducing the average monthly check from $1,907 to roughly $1,468. No president has allowed this to happen, and political consensus holds that Congress will act before the deadline. But the “solution” will almost certainly involve either higher taxes, later retirement ages, or general revenue subsidies — each of which either widens the deficit or imposes costs elsewhere.

The most revealing way to see the entitlement wave is as a share of total federal spending. In 2000, transfer payments were 58% of all federal expenditures. By 2024, they were 62%. That four-percentage-point shift may sound small, but on a $7 trillion spending base, it represents an additional $280 billion per year flowing to benefits rather than discretionary programs. Defense’s share fell from 17% to 12%. Non-defense discretionary (education, transportation, science, housing) fell from 11% to 6%. The budget is slowly but inexorably being consumed by benefit payments.

This shift has profound consequences for governance. When mandatory spending and interest consume all revenue — as they do today — every discretionary spending decision becomes a borrowing decision. Want to fund the IRS? Borrow. Want to maintain highways? Borrow. Want to fund the National Institutes of Health? Borrow. The government cannot invest in its own future without taking on more debt, because the present claims of retirees and bondholders absorb every tax dollar before it reaches a single active program. The budget has become a transfer machine with a military attached, all of it financed by an ever-growing line of credit.

The COVID pandemic provided a preview of what crisis spending looks like in an already-stretched budget. In 2020, transfer payments spiked from $3.01 trillion (2019) to $4.34 trillion as stimulus checks, enhanced unemployment benefits, and PPP forgivable loans flowed to individuals. The remarkable thing is that the spike became the floor. After the pandemic programs expired, transfer payments did not fall back to pre-COVID levels. They settled at $4.40 trillion in 2024 — higher than the crisis peak — because the underlying growth in Social Security and Medicare absorbed the decline in temporary programs. The ratchet only turns one way.