On November 4, 2021, the Occupational Safety and Health Administration (OSHA) issued an Emergency Temporary Standard (ETS) requiring employers of 100 or more to adopt COVID-19 policies, maintain rosters of vaccinated employees, and provide paid time off to employees to vaccinate or recover from its effect. These mandates were to go into effect on January 10, 2022. By February 9, 2022, employers were to require employees to show proof of COVID-19 vaccination or undergo weekly testing.

On that same date the Centers for Medicare & Medicaid Services (CMS) issued an interim rule mandating COVID-19 vaccination and other requirements for workers in most healthcare settings participating in Medicare and Medicaid programs by January 22, 2022.

Legal challenges quickly wound their way through the federal courts, leaving businesses in limbo about their obligations to implement these vaccination and testing mandates. On January 13, 2022 the Supreme Court of the United States (SCOTUS) issued decisions on both mandates, imposing a stay on the OSHA ETS vaccination and testing mandates, but upholding the vaccination mandate and other aspects of the CMS for healthcare facilities.