Esther Sung, a senior litigator at the Justice Action Center and one of the attorneys who represented the plaintiffs at Saturday's hearing, told reporters after the ruling that "we're very grateful that the court recognized the need to block the health care ban immediately".
The lawsuit, filed in US District Court in Portland, Oregon, claims that the proclamation will bar hundreds of thousands of immigrants from coming to the United States, and as a result, could separate families who are immigrating via family-sponsored visas.
A federal judge in OR issued a temporary restraining order on Saturday that prevents a Trump administration rule from going into effect that would've barred visa-seekers who can't pay for their own health care within 30 days of entering the United States.
Under the rule, an immigrant can not get a visa if they are covered by subsidies from the Affordable Care Act (ACA), as those are paid for by the federal government.
Judge Simon will rule on the merits of the case on a later date yet to be set. The Saturday ruling was the latest in a string of court decisions to derail President Donald Trump's initiatives aimed at limiting the admission of certain legal immigrants into the United States.
President Donald Trump signed the proclamation in October for the rule that pertains to people who are already overseas and seeking visas, and not those who are already in the country. It does not apply to asylum-seekers, refugees or children.
The Trump administration wanted the new legislation in order to stop taxpayers from bearing the "substantial costs in paying for medical expenses incurred by people who lack health insurance or the ability to pay for their healthcare".
The policy is part of Mr Trump's effort to shift the U.S. away from a family-focused immigration system. Experts on American health care policy have countered that assertion by pointing out that immigrants are less likely to use America's health care system than American citizens. Unlike the president, these judges controlling our immigration policies from the bench are not accountable to the American people.
Under the government's visa rule, the required insurance can be bought individually or provided by an employer and it can be short-term coverage or catastrophic.
Trump had justified the policy on the grounds that immigrants were more likely to be uninsured, asserting that too many non-citizens were taking advantage of America's "generous public health programs". Medicaid or Affordable Care Act subsidies do not qualify as "approved health insurance" under the proclamation. Visas are also known as green cards and officially as Permanent Resident Cards.