A judge for the US District Court for the District of Oregon issued a nationwide preliminary injunction on Tuesday blocking a rule issued by the Trump administration that would have prevented immigration to the US by anyone who could not demonstrate that they had health insurance coverage.

The Trump administration announced at the beginning of October that they would begin blocking entry to immigrants who lacked private health insurance coverage or who failed to demonstrate the ability to obtain coverage within 30 days of entry to the country. President Donald Trump justified the rule by saying that immigrants without coverage created a “burden to the United States healthcare system” that imposed severe costs on US taxpayers. The rule was immediately challenged in court by the Justice Action Center, a nonprofit immigration advocacy group, and Oregon District Court judge Michael Simon issued a temporary retraining order blocking the rule from taking effect for 30 days in early November.

Simon extended the restraining order into a full nationwide preliminary injunction on Tuesday. Though he refused to rule on the merits of whether the ban was good public policy, Simon said that the rule “was not issued under any properly delegated authority” and could not be enforced as a result. According to Simon, Congress had set forth the criteria under which a person attempting to immigrate to the US could be denied entry in the Immigration and Nationality Act and only Congress could amend those criteria. Congress has not delegated the authority to create new criteria to the President and therefore Trump’s addition of health insurance coverage as a requirement to immigrate into the country was unlawful.