An empty parking lot at Microsoft headquarters in Redmond in in December 2020. (GeekWire Photo / Todd Bishop)

Microsoft says it will require proof of COVID-19 vaccination for all employees, vendors and guests entering its U.S. buildings starting in September, joining Google, Facebook and other companies in implementing such a policy.

In addition, the company said Tuesday morning that the full reopening of its U.S. workplaces will now take place no earlier than Oct. 4.

“As we have done since the beginning of the pandemic, we continue to closely track new developments and adapt our plans as this situation evolves, keeping employee health and safety top of mind,” a Microsoft spokesperson said in a statement Tuesday morning. “We continue to review the situation on a local basis in each region/country/state where we work and will adjust dates and policies as needed.”

Microsoft says it will offer accommodations for employees with medical conditions or other protected reasons, such as religion, that prevent them from getting vaccinated.

The company started bringing back employees in March. Previously its earliest expected date for a full reopening was Sept. 7.

Seattle-based online real estate company Redfin had likewise planned a broad reopening of its headquarters and field offices for Sept. 6, but told employees this morning that the milestone would be pushed back indefinitely for now, promising to give them at least 30 days notice of the new date. Those working in the office must be vaccinated, and the company is asking those who haven’t been fully vaccinated to work from home.

These steps come amid growing concerns over the spread of the Delta variant of COVID-19 in the United States, including the Seattle region.

Amazon said recently that it is requiring employees who have not been vaccinated to wear masks in offices. The Seattle tech giant in June adjusted its return-to-work plans for corporate employees, issuing guidance that will allow for a mix of remote and in-person work. Earlier it had called for a “return to an office-centric culture.”

Contacted by GeekWire this morning, Amazon said it’s continuing to monitor the situation closely and will follow the guidance of local officials and healthcare professionals.

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