Delta Air Lines CEO Ed Bastian notified employees Wednesday that they will face $200 monthly increases on their health insurance premiums starting Nov. 1 if they aren’t vaccinated against Covid-19, citing steep costs to cover employees who are hospitalized with the virus.

Unvaccinated employees will face other restrictions, including indoor masking effective immediately and weekly Covid-19 tests starting Sept. 12 the Atlanta-based airline said in announcing new Covid policies for employees.

The measures are the latest attempt by a U.S. corporation to drive up Covid vaccination rates. Delta stopped short of an outright mandate like rival United Airlines established earlier this month. The airline, which self insures its employees, stands out in its plans to raise premiums for unvaccinated workers to cover the higher costs of insuring employees who get Covid.