Washington — A rule proposed by the Trump administration is prompting immigrant families — including U.S. citizens — to avoid or drop food, medical and housing benefits provided by the government out of fear that enrollment would prevent family members from securing permanent residency, according to a new report.

A study by the Urban Institute found that more than 13% of adults in immigrant families said they were not participating in public programs such as food stamps and subsidized housing due to concerns that the so-called "public charge" rule being finalized by the government would hinder their ability to obtain green cards. The number of immigrants reporting this fear has risen to 20.7% among low-income families.

The report, based on interviews with nearly 2,000 adult immigrants in December 2018, is the first national study to quantify the "chilling effect" immigration advocates and medical practitioners have denounced since a draft of the controversial rule surfaced in 2017. The proposal was published to the Federal Register last fall and the government is expected to roll out and implement a final rule this year.

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Rep. Nanette Barragán of California, the state with the largest foreign-born population in the U.S., said the report's findings demonstrate that the proposed rule change is having the "intended effect" she believes President Trump desires: to sow fear in immigrant communities across the country.

"I think it's pretty troubling to see that families are not using the services they are entitled to because of fear," she told CBS News. "It's kind of despicable to see that the administration is doing everything it can to continue its anti-immigrant agenda."

Expanding a centuries-old standard in immigration law

The "public charge" standard was first codified into U.S. immigration law in 1882 and again in the Immigration and Nationality Act of 1952. The Trump administration is now seeking to expand the definition of the standard and make it more difficult for certain immigrants to secure permanent residency or temporary visas.

Immigration authorities currently ask green card applicants to prove they won't be a burden on the country, but the new regulation, if enacted, would require caseworkers to consider the use of government housing, food and medical assistance such as the widely-used Section 8 housing vouchers, the Supplemental Nutrition Assistance Program (SNAP) and Medicare's Part D prescription drug coverage.

The more than 400-page proposal would subject immigrant households who fall below certain income thresholds to the "public charge" test — which would also consider how well applicants speak, read and write English. Under the proposed rule, which received 216,097 comments during a 60-day public comment window, any diagnosed medical condition that requires extensive medical treatment would also "weigh heavily" in evaluations by caseworkers.

Asylum seekers and refugees would be exempt from the proposed rule.

The administration has cast the proposal as one that fosters "self-sufficiency" among immigrants. In a statement to CBS News, U.S. Citizenship and Immigration Services (USCIS) Director Francis Cissna said the proposed rule is a "necessary step" to enforce centuries-old laws that "require" immigrants to "be able to care for themselves without being a public charge."

Democrats and immigration advocates, meanwhile, have strongly opposed the proposed regulation, which they believe will punish poor immigrants for using essential government benefits and prompt some parents to halt their children's enrollment in nutritional and medical programs.

Another concern raised by Democrats is that the rule's "chilling effect" could also harm U.S. citizens and residents not subject to the "public charge" test.

"Confusion" and "disaster"

Although the proposed rule would affect immigrants in the U.S. who are not citizens or permanent residents — as well as people seeking to immigrate to the country from abroad — the report by the Urban Institute detailed a "spillover effect" in which both green card holders and U.S. citizens reported avoiding public benefits because of the proposal's expected implementation.

Nearly 15% of immigrants in families in which all members had green cards and 9.3% of adults in families comprised of naturalized U.S. citizens said they did not participate in government assistance programs within the past 12 months due to concerns about the proposed rule's impact on their and their family members' ability to qualify for permanent residency.

Hamutal Bernstein, a senior research associate at the Urban Institute and one of the report's authors, told CBS News the fear experienced by these immigrants who would theoretically not be directly affected by the rule stems from the proposal's complex provisions.

"The spillover we see is a product of a lot of misunderstanding and confusion about what is a very complicated rule," she explained.

The report also found that immigrant families with children were more likely to report "chilling effects" than those comprised solely of adults. In another study last year, the Urban Institute estimated that as many as 6.8 million U.S. citizen children enrolled in Medicaid and the Children's Health Insurance Program (CHIP) with non-citizen parents could be affected by the rule change.

Although the proposal does not include Medicaid and CHIP assistance in its "public charge" considerations, researchers said immigrant parents, particularly in Latino and Asian American communities, could drop these benefits due to concerns surrounding their ability to remain in the U.S. legally with their U.S.-born children.

Bernstein suggested the latest report outlined a modest estimate of the impact of the proposal since the study excluded adults in immigrant households who did not speak English or Spanish. She said the share of immigrant families avoiding public benefits is also likely to increase once the rule is finalized and more people become aware of it.

"Without a rule being finalized or being implemented, we're already seeing evidence of chilling effects," she said. "Our guess would be that once a rule is finalized — and possibly implemented — the chilling rates could be much higher."

A USCIS spokesperson did not specifically address questions about the proposal's "chilling effects" in immigrant communities and whether it had been subject to a review by other federal agencies that administer government benefits. The spokesperson also did not provide a timeline on when the rule would be finalized and implemented.

For Barragán, the California Congresswoman, the key for Democrats and immigration activists is to help clarify "myths" prevalent in immigrant communities about the proposed rule. She said they are facing similar dilemmas with the potential addition of a citizenship question to the 2020 Census and a newly-unveiled proposal by the Department of Housing and Urban Development (HUD) to evict undocumented immigrants — and potentially tens of thousands of U.S. children — from government-subsidized housing.

"If you're seeing this trend already happening with the public charge rule, if the housing rule goes into effect, you're going to see disaster, like more homelessness; you're going to see more citizens on the street. That's insane to me," she said.