The U.S. Supreme Court issued two highly anticipated rulings on Thursday, temporarily blocking a Biden administration COVID-19 vaccine mandate for large employers but allowing a separate rule applying only to health care workers at facilities receiving federal funding.

The high court settled the matter concerning large employers in a 6-3 decision to block the rule that would have been issued by the Occupational Safety and Health Administration, with the three liberal justices dissenting.

"OSHA has never before imposed such a mandate. Nor has Congress. Indeed, although Congress has enacted significant legislation addressing the COVID–19 pandemic, it has declined to enact any measure similar to what OSHA has promulgated here," the majority opinion stated.

As for health care facilities, the court ruled 5-4 to uphold for now the rule administered by the Department of Health and Human Services, with Justices Clarence Thomas, Samuel Alito, and Neil Gorsuch dissenting.

"Both Medicare and Medicaid are administered by the Secretary of Health and Human Services, who has general statutory authority to promulgate regulations 'as may be necessary to the efficient administration of the functions with which [he] is charged.' One such function — perhaps the most basic, given the Department’s core mission — is to ensure that the health care providers who care for Medicare and Medicaid patients protect their patients’ health and safety," the majority stated.

The rulings take effect immediately and will remain in place until legal challenges over their constitutionality are resolved through the justice system, and possibly through the Supreme Court.

A mandate targeting half the U.S. workforce

The administration’s employer mandate, announced by senior officials in early November, with an original effective date of Jan. 4, targets about 84 million U.S. workers, or roughly half of the U.S. workforce. Its deadline for employers to require masking was extended to Jan. 10. Full compliance, which the court’s decision now renders renders unenforceable, had been extended to Feb. 9.

Administered by OSHA, the emergency temporary standard would have imposed penalties on U.S. employers with 100 or more workers that failed to ensure that all of their employees, aside from those who qualified for an exemption, were fully vaccinated for COVID-19, or tested for the virus, each week. Employers could choose whether to offer a testing option and wouldn't have had to pay for tests. Unvaccinated workers would have had to wear a mask at work.

“For all intents and purposes, the ETS is now ‘dead’ until the 6th Circuit Court of Appeals rules on the merits of the rule, or OSHA promulgates a rule consistent with the notice and comment requirements,” Dan Kaplan, a partner and litigation attorney with Foley & Lardner LLP and co-chair of the firm’s large business side labor & employment practice, told Yahoo Finance. Kaplan anticipates that employers that had not contemplated mandatory vaccination programs for fear of losing labor, are now much less implement any form of vaccination mandate or requirement.

Heath facility mandate targets 17 million heath care facilities

The administration’s health care mandate applies to facilities that receive Medicare or Medicaid funds, requiring them to maintain a fully vaccinated workforce, with no testing alternative. The rule for health workers applies to more than 10.4 million workers and is administered by Heath and Human Services' Centers for Medicare & Medicaid Services.

Norma W. Zeitler, a partner at Barnes & Thornburg, explains that the court's decision impacting health care workers allows the administration to enforce vaccination requirements on covered health care facilities, with certain exceptions to accommodate workers who decline vaccination on medical or religious grounds.

"In late November, lower courts in Missouri and Louisiana issued a stay, thus halting enforcement of the CMS mandates — but only in the states that had joined the lawsuits. As a result, the CMS vaccine mandate was in effect in some states but not others," Zeitler said. "Today, the Supreme Court lifted the stays of enforcement, paving the way for the CMS to enforce its vaccine mandate nationwide."

The high court’s ruling on Thursday addressed only the narrow issue of whether the states and business groups seeking to invalidate the mandates as unconstitutional can keep them from being carried out until courts determine the legality of the mandates themselves. Aside from the mandates, courts have widely upheld decisions by private companies to adopt their own vaccination and testing requirements, including those that are considered more restrictive.

The cases National Federation of Independent Business v. OSHA and Ohio v. OSHA were consolidated to address enforcement of the employer mandate, while the cases Biden v. Missouri and Becerra v. Louisiana were consolidated to address enforcement of the health care mandate.

A single agency 'cannot commandeer businesses'

Challengers say that in directing OSHA and CMS to adopt vaccination requirements, the Biden administration overstepped its executive authority. Congress never delegated such power to the executive branch, they argue.

The majority opinions issued on Thursday offer a window into how likely those arguments are to succeed.

"Agreeing that applicants are likely to prevail, we grant their applications and stay the rule," the majority wrote in its decision concerning the large employer mandate.

Conversely, the majority's opinion concerning the heath facility ETS described the policy as a "straightforward and predictable example" of health and safety regulation that Congress authorized HHS' Secretary to impose.

“Businesses have encouraged and incentivized their employees to get vaccines. But a single federal agency tasked with occupational standards cannot commandeer businesses, economy-wide, into becoming de facto public health agencies,” attorney Scott E. Keller argued on Friday on behalf of a group of business organizations seeking to block enforcement of the OSHA rule.

Benjamin M. Flowers, solicitor general for the state of Ohio, argued on behalf of the group that the administration’s industry-wide application is too broad, exceeding its authority to regulate activities limited to those present while employees are on the job.

“It's not truly intended to regulate a workplace danger; it's a danger that we all face simply as a matter of waking up in the morning,” Flowers argued.

Justice Department solicitor general Elizabeth B. Prelogar argued that OSHA’s authority does extend to required immunizations, masking, and testing.

“The applicants try to portray this standard as unprecedented. But this lies in the heartland of OSHA's regulatory authority,” Prelogar told the court. “Congress charged the agency with setting nationwide standards to protect the health and safety of employees throughout the nation, and Congress specifically appropriated money to OSHA to address COVID-19 in the workplace.”

Alexis Keenan is a legal reporter for Yahoo Finance. Follow Alexis on Twitter @alexiskweed.

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