On June 17, 2020, the U.S. Equal Employment Opportunity Commission (EEOC) issued guidance (see A.7.) stating employers cannot require workers to undergo Coronavirus Disease 2019 (COVID-19) antibody testing (as distinguished from testing for the COVID-19 virus itself). Increased COVID-19 antibody (or “serology”) testing has been cited as a helpful tool because it aids in understanding the prevalence of the virus in the general population. It can also produce useful information about populations that may have some level of immunity from the virus. But the EEOC has now made clear that employers may not mandate such testing, as doing so violates the Americans with Disabilities Act (ADA).