SEATTLE — Amazon joined a growing list of large employers delaying the date that workers will return to its offices as the highly contagious delta variant of the coronavirus continues to spread.

But unlike many of those large employers, Amazon is not requiring workers to be vaccinated.

Amazon told workers in its corporate buildings this morning that they would not need to return to their offices until Jan. 3. The company had previously said they’d need to begin coming in regularly starting Sept. 7.

The delay does not apply to warehouse employees, who have continued to work at their facilities throughout the pandemic.

Although Amazon isn’t mandating vaccinations, it will require office employees who have not verified that they’ve been fully vaccinated to wear masks at work, spokesman Jose Negrete said via email.

(Amazon founder Jeff Bezos owns The Washington Post.)

The decision not to require vaccinations runs counter to the approach of other tech giants. Last month, Google and Facebook announced that they would require employees who work in their offices to be fully vaccinated. And earlier this week, Microsoft announced plans to fully open its offices Oct. 4 and require workers to prove that they have been vaccinated, after previously saying it would not do so.

Amazon, the country’s second-largest employer after Walmart, is one of the biggest employers to delay the return to its offices as far out as it has. Last month, ride-sharing company Lyft told employees that they would need to return to its offices Feb. 2. It also said it would require proof of vaccination.

Amazon’s warehouse staff will continue to stow, pick and pack items at its facilities. The company employs more than 1.3 million workers worldwide, including 950,000 people in the United States, it said in releasing its financial results last week.