Employees at Google have been threatened with pay loss and even termination of employment if they fail to comply with the company’s Covid-19 vaccination policy, according to internal documents obtained by CNBC.

Leaders circulated a memo on December 3 asking employees to upload proof of vaccination or apply for a medical exemption or religious exemption. Those who had not uploaded their vaccination status or were unvaccinated, or whose exemption requests were not approved, will be contacted after the date.

Those who don’t meet vaccination requirements by the January 18 deadline will be put on “paid administrative leave” for 30 days, according to the document. Afterwards, their employment will be terminated and they will be put on “unpaid personal leave” for up to six months.

Google is requiring its employees at some point in the new year to eventually come into physical offices three days a week, while much of the tech industry continues to delay return-to-work plans.

The government has little patience for people who refuse vaccines, which have been widely available for months. By the end of January, companies with 100 workers or more must ensure their workers have been fully vaccinated or have been regularly tested for Covid-19. Early November, a federal court issued a stay on the order, halting the administration’s efforts.

Nevertheless, Google is asking 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, and the company indicates that it will follow Biden’s orders.

According to Google’s memo, almost all roles at the company will be covered by the executive order. In the statement from Google, the company said, “Anyone entering a Google building must have a current vaccination certificate or an approved accommodation allowing them to work or come on-site.” In addition, “frequent testing does not replace vaccination.”

Google and its parent company Alphabet are staunch supporters of vaccines. In July, CEO Sundar Pichai announced that employees returning to work would have to be vaccinated. In January, the company planned to reopen. In early December, Google told U.S. workers it would not be requiring them to return to work yet, amid ongoing concerns about infection numbers.

Although leadership encouraged employees to come in “where conditions permit them to connect in person with colleagues and start regaining the muscle memory of being in the office more frequently.”

Employees are not universally accepting of the vaccine mandate. The Google leadership claims its requirements will apply to all employees, even those who work from home, who engage directly or indirectly with federal government contracts. A manifesto signed by several hundred Google workers opposes the policy.

Google provides recommendations for people who don’t want to get vaccinated in the latest guidance. A Google spokesperson said employees could “explore” roles that do not conflict with the executive order. Those with religious beliefs or medical conditions can also request exemptions, which Google previously said would be granted on a case-by-case basis.