The Supreme Court on Thursday blocked the Biden administration from enforcing its sweeping vaccine-or-test requirements for large private companies, but allowed a vaccine mandate to stand for medical facilities that take Medicare or Medicaid payments.

The rulings came three days after the Occupational Safety and Health Administration’s emergency measure for businesses started to take effect.

The mandate required that workers at businesses with 100 or more employees get vaccinated or submit a negative Covid test weekly to enter the workplace. It also required unvaccinated workers to wear masks indoors at work.

“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 court wrote in an unsigned opinion.

“Requiring the vaccination of 84 million Americans, selected simply because they work for employers with more than 100 employees, certainly falls in the latter category,” the court wrote.