As Congress struggles to ensure Social Security is fully funded far into the future, it will have a new problem to deal with. If President Trump carries out his vow to deport all illegal immigrants in the U.S., Social Security will face a more significant deficit.

Studies by think tanks and the Congressional Budget Office have shown the Social Security Administration (SSA) receives billions each year from an unexpected source: Legal and illegal immigrants. Some economists project a broad drag on the economy as a result of Trump’s actions — and it could cost Social Security roughly $20 billion in cash flow annually, according to actuaries at the SSA, which sends benefits to 68 million Americans each month, totaling $1.5 trillion last year alone.

Foreign-born workers in the United States contribute to Social Security at the same tax rate as everyone else but have lower predicted Social Security benefits than native-born Americans because, on average, they earn lower lifetime wages and have fewer years of employment that count toward their calculated benefits.

In addition, recent trends suggest that foreign-born workers are increasingly returning to their home countries to retire. As a result, many who pay into the Social Security system during their working years may not be eligible to receive benefits because non-residents can only do so under certain circumstances. Foreign-born contributors can generate net gains for the Social Security trust fund by not fully drawing benefits. 

As far as illegal immigrants are concerned, in 2022, they contributed $25.7 billion in Social Security taxes, typically by working under borrowed or fraudulent Social Security numbers. Unauthorized immigrants, however, are ineligible to claim Social Security benefits. Source: The Senior Citizens League, a non-profit advocacy organization supporting older adults’ benefits.