On November 4, 2021, the Occupational Safety and Health Administration (OSHA) released its much-anticipated Emergency Temporary Standard (ETS) regarding COVID-19 vaccination and testing requirements for large US employers, i.e., those employers with 100 or more employees. The ETS requires covered employers to either (1) devise, implement and enforce a mandatory COVID-19 vaccination policy or (2) instead adopt a policy requiring employees “to elect either to get vaccinated or to undergo regular COVID-19 testing and wear a face covering at work.” In either instance, covered employers must be prepared to implement and comply with the requirements outlined in the ETS by December 5, 2021, and January 4, 2022, as applicable. This Legal Update provides further detail on the ETS requirements.