Millions of Americans are now or will soon be required to get vaccinated under new federal mandates.

Federal employees, government contractors and health-care workers are covered under new Biden administration rules that allow medical and religious exemptions but generally do not allow regular testing and masking in lieu of vaccination.

An emergency order from the Occupational Safety and Health Administration (OSHA), which affects employees at companies with 100 or more workers not covered by other federal mandates, does allow for testing and masking.

The mandates have stirred political and legal brawls across the nation, pitting states against the federal government, local governments against their states, and employees against employers. The mandates for health-care facilities and private employers have both been blocked in courts, though the cases still must work their way through the appeals process. Critics have said the requirements constitute federal overreach and force Americans to choose between their livelihoods and medical autonomy.

The Biden administration says mandates will “save lives, protect the economy, and accelerate the path out of the pandemic.”