December 17, 2021: According to internal documents viewed by CNBC, Google has told its employees that they will lose pay and will eventually be fired if they don’t comply with the company’s Covid-19 vaccination policy.

A memo circulated by leadership said employees had until December 3 to declare their vaccination status and upload documentation showing proof or applying for a medical or religious exemption. The company said after that date, it would start contacting employees who hadn’t uploaded their status or were unvaccinated and those whose exemption requests weren’t approved.

The document said employees who haven’t complied with the vaccination rules by the January 18 deadline would be placed on “paid administrative leave” for 30 days. After that, the company will put them on “unpaid personal leave” for up to six months, followed by termination.

While much of the tech industry continues to push back return-to-work plans and companies large and small prepare for a flexible future, Google requires its workforce to eventually come into physical offices three days a week at some point in the new year. And it’s showing limited patience for those who refuse to get vaccines, which have been widely available for months.

The Biden administration has ordered U.S. companies with 100 or more workers to ensure their employees are fully vaccinated or regularly tested for Covid-19 by January 18. In early November, a federal court issued a stay-on order, putting a halt to the administration’s efforts.

Still, Google asked its more than 150,000 employees to upload their vaccination status to its internal systems, whether they plan to come into the office or not. The company indicated that it intends to follow Biden’s order.

“We expect that almost all roles at Google in the U.S. will fall within the scope of the executive order,” Google’s memo said. “Anyone entering a Google building must be fully vaccinated or have an approved accommodation that allows them to work or come onsite,” the company said, adding that “frequent testing is not a valid alternative to vaccination.”

CEO Sundar Pichai announced in July that the company would require vaccinations for those returning to offices. At the time, the plan was to reopen in January. But in early December, amid ongoing concerns about infection numbers, Google told U.S. employees it would not yet require them to return to offices. However, leaders encouraged employees to continue coming in “where conditions allow them to reconnect with colleagues in person and start regaining the muscle memory of being in the office more regularly.”

Employees have not universally accepted the vaccine mandate. Several hundred Google workers have signed and circulated a manifesto opposing the company’s requirements, which leadership said would apply to all employees, even those working from home, who engage directly or indirectly with federal government contracts.