Immigrants Use Less Welfare at Every Income Level

"Was this study all immigrants or undocumented?"

All. But, I believe the programs they are looking at aren't accessible to illegal immigrants, unless they're obtained through fraud. Immigrants are 15% of the population but commit 5% of the welfare fraud; that's from another Cato study: www.cato.org

There's also this:
Immigrant and Native Consumption of Means-Tested Welfare and Entitlement Benefits in 2023
www.cato.org

Noncitizen immigrants"including those lawfully present in the United States on various temporary visas, lawful permanent residents, and illegal immigrants"consumed 53 percent less welfare than native-born Americans. Noncitizens were 7.5 percent of the population and consumed just 3.2 percent of all welfare. However, naturalized immigrants consumed 20 percent more welfare than native-born Americans because they were an older population"they consumed 6.6 times more Social Security and 5.4 times more Medicare than noncitizens on a per capita basis. Naturalized immigrants were 7.2 percent of the population and consumed 8 percent of welfare benefits.

And
"Other studies evaluating immigrant welfare participation and consumption use the household as the unit of analysis for all programs.9 However, we dispute this approach because many spouses and children of immigrants are native-born Americans."

See Also, and this is from a different source, hence the "high rate" comment:
cis.org
The high welfare use of immigrant households is not explained by an unwillingness to work. In fact, 83 percent of all immigrant households and 94 percent of illegal-headed households have at least one worker, compared to 73 percent of U.S.-born households.

@#13 ... You missed the part where they're a net economic positive. ...

Immigrants' Recent Effects on Government Budgets: 1994"2023
February 3, 2026 White Paper
www.cato.org

... Recent increases in immigration have rekindled concerns about their effects on government budgets. This paper updates a model of these effects first developed by the National Academies of Sciences, Engineering, and Medicine (NASEM) to shed light on how immigrants, both legal and illegal, and their children affect government budgets.

This analysis is the first to estimate the cumulative fiscal effect of immigrants on federal, state, and local budgets over 30 years.

The government first began gathering detailed information on benefits use by citizenship status in 1994. The data show:

- - - For each year from 1994 to 2023, the US immigrant population generated more in taxes than they received in benefits from all levels of government.

- - - Over that period, immigrants created a cumulative fiscal surplus of $14.5 trillion in real 2024 US dollars, including $3.9 trillion in savings on interest on the debt.

- - - Without immigrants, US government public debt at all levels would be at least 205 percent of gross domestic product (GDP)"nearly twice its 2023 level. ...