With the first doses of Pfizer’s COVID-19 vaccine now being administered in the U.S., the federal government is giving employers around the country the green light to require immunization for most workers.

In general, companies have the legal right to mandate that employees get a COVID-19 shot, the Equal Employment Opportunity Commission (EEOC) said Wednesday. More specifically, employers are entitled – and required – to ensure a safe workplace in which “an individual shall not pose a direct threat to the health or safety of individuals in the workplace.”

That can mean a company requiring its workforce to be vaccinated.

The Americans with Disabilities Act limits an employer’s ability to require workers to get a medical examination. But the EEOC’s latest guidance clarifies that getting vaccinated does not constitute a medical exam. As a result, ordering employees to get a COVID-19 shot would not violate the ADA.

Not all employees must get vaccinated, according to the agency. Employees with either a disability or “sincerely held” religious beliefs that prevent them from getting inoculated are exempt, according to the EEOC, which is charged with enforcing laws against workplace discrimination.

“If they do require it, an employee can make a request for an accommodation under the Americans with Disabilities Act or Title VII, and if they do request the accommodation, the employer has an obligation to see if accommodation is possible,” said Helen Rella, a workplace attorney at Wilk Auslander, a New York law firm.

In cases like these, an employer must attempt to make a reasonable accommodation for the worker, like allowing them to work from home, for example. If that’s not possible, however, and unvaccinated individuals pose a potential threat to either themselves or to others, a company has the right under employment law to exclude them from physically entering the workplace.

Notably, that doesn’t mean an employer may summarily fire a worker who declines to be vaccinated. They could be eligible for unpaid leave or other similar entitlements under federal, state and local laws, according to the EEOC.