On January 13 in two highly anticipated decisions, the U.S. Supreme Court first reinstated an injunction blocking implementation of the Occupational Safety and Health Administration’s COVID-19 emergency temporary standard (ETS). It was set to require employers with 100 or more employees to mandate vaccination of workers or require weekly testing by February 9. The court then upheld the Centers for Medicare & Medicaid Services’ (CMS) mandatory vaccination rule affecting health care employers that participate in those programs.

The Supreme Court voted 6-3 to reinstate the district court stay of OSHA’s COVID-19 vaccinate or test mandate. This means that the rule is effectively dead unless the agency decides to issue a substantially reduced regulation. The legal grounds in the opinion were narrow. The Supreme Court majority concluded that the underlying OSHA statute does not give the agency the authority to regulate a hazard that is not particular to the workplace. “A vaccination, after all, ‘cannot be undone at the end of the workday,’” the court wrote, citing an older case.

Practically, this means that employers can stop compliance activities related to the ETS. OSHA may decide to issue a reduced rule, perhaps keeping the masking and paid leave requirements, or tailoring the rule to specific industries with increased risk of exposure. (The Supreme Court indicated that would be allowed).

The CMS rule was upheld 5-4. Unlike the OSHA ETS, the majority opinion concluded that CMS rule fell within its authority to require practices that protect health care workers and their patients, due to particular risks faced by that industry. CMS may issue an amended timetable for compliance with the rule given the delays resulting from the litigation.

Employers that have partially implemented the ETS should decide how they will react to this decision. Laws in some states may prohibit employers from voluntarily implementing mandatory vaccination requirements. Other states may issue their own workplace safety rules to mandate vaccinations, testing, or other aspects of the rejected federal ETS. Employers should consider how policy changes will be received by their employees, who may have opposing positions with regard to the company’s efforts to control COVID-19 exposure in the workplace.