But the court upheld a separate mandate for almost all employees at hospitals, nursing homes and other health care providers that receive federal funds.

Transcript

ARI SHAPIRO, HOST:

The U.S. Supreme Court has blocked President Biden's vaccine or test mandate for large private companies. Today, it essentially ruled that OSHA, the federal workplace safety agency, exceeded its authority with the mandate. But the court also handed the White House a victory for its COVID plan. It upheld the Biden administration's vaccine mandate for health care workers at facilities that receive federal funding.

NPR legal affairs correspondent Nina Totenberg is here to sort through this mixed ruling. Hi, Nina.

NINA TOTENBERG, BYLINE: Hi, Ari.

SHAPIRO: What did this regulation from OSHA, the Occupational Safety and Health Administration, actually say?

TOTENBERG: It said that beginning this week, employers with a hundred or more workers had to either vaccinate their workers, with the federal government footing the bill, or test them weekly. The court, in an unsigned opinion, said that Congress had not given the agency such broad authority. Quote, "although Congress has indisputably given OSHA the power to regulate occupational dangers, it has not given that agency the power to regulate public health more broadly," the majority said.

Requiring the vaccinations of 84 million Americans simply because they work for employers with more than a hundred employees certainly is too broad. But the court did say that the agency could impose this sort of a regulation in a more targeted way, quote, "where the virus poses a special danger because of the particular features of an employee's job or workplace."

SHAPIRO: What does that mean? What kind of features or employers might the court be talking about there?

TOTENBERG: What the court likely means - and this came up at the oral argument - is that this might be a reasonable regulation where employees work closely together - for instance, manufacturing sites, meatpacking plants, perhaps even offices where workers sit side by side.

SHAPIRO: You said this was an unsigned opinion. Do we know what the vote count was?

TOTENBERG: Yes. It was 6-3 with the court's three liberals dissenting. They said that by striking down OSHA's regulation, the court, quote, "stymies the federal government's ability to counter the unparalleled threat that COVID-19 poses to our nation's workers."

SHAPIRO: What's the impact of this going to be?

TOTENBERG: Well, the decision to invalidate the regulation comes as COVID-19 cases reached a new high of $1.4 million in - million cases in a single day earlier this week. That has swamped hospitals across the country, flooding them mainly with unvaccinated patients, and the situation has been so serious as to prompt some governors to call out the National Guard to help, even as other governors in Republican-dominated states have made vaccine mandates illegal.

SHAPIRO: But the justices went a different way in the case involving health care workers. What did they say there?

TOTENBERG: In stark contrast to the decision in the OSHA case, the court voted 5-4 in the CMS case - the Centers for Medicaid and Medicare Services - they voted that in that - the CMS regulation to uphold mandatory vaccinations for Medicare and Medicare providers. The court's three liberals were joined by the Chief Justice John Roberts and Justice Brett Kavanaugh in the majority, and they upheld the CMS regulation.

The court said the vaccine mandate for health care workers was unlike the OSHA regulation because it was justified in the spending clause of the Constitution, which allows the federal government to impose conditions when it provides funding for programs like Medicare and Medicaid. And the court said the regulation clearly served to protect patients from being exposed to greater risks when they're in a hospital, nursing home, being cared for by other health entities. As the majority put it in a separate unsigned opinion, the rule, quote, "fits neatly within the language of the statute. After all, ensuring that providers take steps to avoid transmitting a dangerous virus to their patients is consistent with the fundamental principle of the medical profession - first, do no harm. It would be the very opposite for a facility that's supposed to make people well to make them sick with COVID-19."

And the dissenters were four of the court's conservatives - Justices Thomas, Alito, Gorsuch and Amy Coney Barrett.

SHAPIRO: NPR's Nina Totenberg, thank you very much.

TOTENBERG: Thank you. Transcript provided by NPR, Copyright NPR.