Undocumented immigrants pay billions more into Medicare every year than they use in health benefits, and in fact they subsidize care for other Americans, according to researchers.

A study published in the Journal of General Internal Medicine contends that undocumented immigrants generated surplus Medicare contributions of $35.1 billion from 2000 to 2011, extending Medicare’s estimated life span by one full year. The study appeared earlier this month as an "online first" article in the Journal of General Internal Medicine and will appear in a forthcoming print edition of the journal.

Researchers from Harvard Medical School, the Institute for Community Health and City University of New York’s School of Public Health at Hunter College found that in one year alone — 2011 — undocumented immigrants generated an average surplus of $316 apiece for Medicare. Other Americans generated an average deficit of $106 apiece. Undocumented immigrants contributed $3.5 billion more than they received in care in 2011, according to the study.

Researchers concluded that restricting immigration would be bad for Medicare’s financial health. They estimated that contributions from undocumented immigrants during the first decade of the century prolonged Medicare’s trust fund solvency by one year. The trust fund is predicted to be insolvent in 15 years.

Undocumented immigrants are not eligible to participate in government health programs, including Medicare and the Affordable Care Act, but they do contribute b