These workers may never draw Medicare benefits because they do not meet the program's eligibility requirements, authors said.
The study challenges the narrative that immigrant workers, particularly those who are undocumented, raise healthcare costs by seeking care in U.S. emergency rooms.
Illegal aliens are disproportionately uninsured, and cannot receive government healthcare benefits, including under President Obama's healthcare law.
Wednesday's study was written by five professors of medicine and public health.
They cautioned against an immigration reform package that would reduce the flow of young workers.
These immigrants are helping to "offset the aging of the U.S. population and the healthcare financing challenge that it presents," study authors wrote.
Liberal advocacy group Public Citizen called this trend a "disgrace" given that most immigrants go without healthcare coverage.
"It is appalling that a third of all immigrants were uninsured in 2010," said Sidney M. Wolfe, director of Public Citizen's Health Research Group. "These are the same people contributing a surplus of well over $10 billion a year to Medicare."