What would be the projected effect on Social Security and Medicare trust funds of deporting all undocumented immigrants and their U.S.-born children?

1. The numbers now: undocumented workers are net payers into the system

Multiple analyses report that undocumented workers contribute tens of billions annually to Social Security and Medicare through payroll taxes even though many will never draw those benefits; figures cited include roughly $13–$26 billion to Social Security in various years and $3–$6 billion to Medicare, with one recent tally at $22.6 billion to Social Security and $5.7 billion to Medicare in 2022 ^{[4] [2] [1] [5]}.

2. Short‑term shock: immediate revenue loss and faster depletion timelines

Modeling exercises that simulate mass removals find that reducing or removing undocumented workers lowers program income and speeds depletion; the Penn Wharton Budget Model projects deportation scenarios that cut revenues, raise deficits by hundreds of billions over decades and move Social Security’s depletion date about six months earlier in some scenarios ^{[2] [6]}.

3. Long horizon: measurable but not catastrophic shifts in actuarial balances

Over 75 years the effect of immigration on Social Security’s actuarial balance is meaningful but modest relative to the total shortfall: Social Security actuaries and bipartisan analysts estimate changes on the order of a few tenths of a percentage point of taxable payroll per large change in net immigration, meaning the 75‑year deficit worsens noticeably under mass deportation but does not, by itself, fully determine solvency outcomes ^{[3] [7]}.

4. Why deportations worsen the math: payroll taxes now, benefits later

The fiscal mechanism is straightforward in the reporting: many undocumented workers pay FICA payroll taxes—sometimes using false or alternate Social Security numbers—so removing them eliminates current contributions while also reducing the working‑age population that supports retirees; because payroll taxes fund current benefits, fewer workers means fewer dollars coming in when Baby Boomers and later cohorts draw down the system ^{[7] [8] [9]}.

5. Medicare’s distinct timeline and contributions

Medicare’s Hospital Insurance (Part A) trust fund faces its own depletion timetable (reportedly in the early 2030s), and immigrants’ payroll contributions help that balance; estimates similarly place undocumented contributions to Medicare in the billions annually, so their removal would reduce HI receipts and could hasten depletion, though precise amounts and timing vary across analyses ^{[8] [1] [10]}.

6. Policy sensitivity and model uncertainty

Projections differ because results depend on assumptions about the number of people removed, whether removals are permanent or temporary, future legal immigration, birthrates of remaining populations, labor force participation and whether deported persons are replaced by new workers; analysts emphasize that increased legal immigration could offset losses while harsh deportation policies that also deter lawful migration would compound negative effects ^{[3] [2] [11]}.

7. Competing framings and implicit agendas in the sources

Advocacy and policy groups emphasize different angles: immigrant‑supporting organizations stress the contribution and solvency benefits of immigrant labor (American Immigration Council, CBPP, Brookings), while groups like CIS frame the payments as “free” contributions because many undocumented people cannot collect benefits—both points are factually reported in the literature but reveal policy agendas about legalization, eligibility and enforcement which shape recommended remedies ^{[12] [13] [8]}.

8. Bottom line: deportation would make solvency problems worse, but not eliminate the need for broader fixes

All credible sources in the set converge that removing the undocumented population would reduce payroll‑tax receipts, worsen Social Security and Medicare trust‑fund balances and likely accelerate depletion timelines (often quantified as months to a few tenths of a percentage point over multi-decade horizons); however, none of the reporting claims deportation alone is the sole cause of insolvency, and analysts warn that durable solvency requires policy choices—tax, benefit or immigration reforms—beyond enforcement alone ^{[2] [3] [5]}.