Some worry that immigrants burden the US economy and particularly the health care system. However, no analyses to date have assessed whether immigrants' payments for premiums and taxes that fund health care programs exceed third-party payers' expenditures on their behalf. To assess immigrants' net financial contributions to US health care programs. This cross-sectional analysis used 2017 data from the Medical Expenditure Panel Survey (MEPS) and the Current Population Survey (CPS) and 2014 to 2018 data from the American Community Survey. The main analyses used data from the calendar year 2017. Data from the calendar years 2012 to 2016 were also reported. Data were analyzed from June 15, 2020, to August 14, 2022. Participants comprised 210 669 community-dwelling respondents to the MEPS and CPS (main analysis) and nursing home residents who were included in the American Community Survey (additional analysis). Citizenship and immigration status. Total and per capita payments for premiums and taxes that fund health care as well as third-party payers' expenditures for health care in 2018 US dollars. Among 210 669 participants, 51.0% were female, 18.3% were Hispanic, 12.3% were non-Hispanic Black, 60.3% were non-Hispanic White, and 9.2% were of other races and/or ethnicities. A total of 180 084 participants were respondents to the 2018 CPS, and 30 585 were respondents to the 2017 MEPS. Among the 180 084 CPS respondents, immigrants accounted for 14.1% (weighted to be nationally representative), with the subgroup of citizen immigrants accounting for 6.8%, documented noncitizen immigrants accounting for 3.7%, and undocumented immigrants accounting for 3.6%; US-born citizens constituted 85.9% of the population. Relative to US-born citizens, immigrants were more often age 18 to 64 years (79.6% vs 58.3%), of Hispanic ethnicity (45.0% vs 14.0%), and uninsured (16.8% vs 7.4%); similar percentages (51.4% vs 50.9%) were female. US-born citizens vs immigrants paid similar amounts in premiums and taxes ($6269 per capita [95% CI, $6185-$6353 per capita] vs $6345 per capita [95% CI, $6220-$6470 per capita]). However, third-party expenditures for immigrants' health care ($5061 per capita; 95% CI, $4673-$5448 per capita) were lower than their expenditures for the care of US-born citizens ($6511 per capita; 95% CI, $6275-$6747 per capita). Immigrants, in general, paid significantly more per person (net contribution, $1284; 95% CI, $876-$1691) than was paid on their behalf. Most of this surplus was accounted for by undocumented immigrants, whose contributions exceeded their expenditures by $4418 per person (95% CI, $4047-$4789 per person). US-born citizens collectively paid $67.2 billion (95% CI, -$2.3 to $136.3 billion) less in premiums and taxes than third-party payers paid for their care. This deficit was mostly offset by the $58.3 billion (95% CI, $39.8-$76.8 billion) net surplus of payments from immigrants, 89% of which ($51.9 billion; 95% CI, $47.5-$56.3 billion) was attributable to undocumented immigrants. In this study, immigrants appeared to subsidize the health care of other US residents, suggesting that concerns that immigrants deplete health care resources may be unfounded.