From the ASA Central Network Digest for Sunday July 19, 2020:
A.6. May an employer administer a COVID-19 test (a test to detect the presence of the COVID-19 virus) before permitting employees to enter the workplace? (4/23/20)
The ADA requires that any mandatory medical test of employees be “job related and consistent with business necessity.” Applying this standard to the current circumstances of the COVID-19 pandemic, employers may take steps to determine if employees entering the workplace have COVID-19 because an individual with the virus will pose a direct threat to the health of others. Therefore an employer may choose to administer COVID-19 testing to employees before they enter the workplace to determine if they have the virus.