Alphabet CEO Sundar Pichai began discussing the company's plans to allow workers back into the office, according to an email sent to employees Monday that was viewed by CNBC.

In the email, Pichai said workers can expect a "staggered" and "incremental" return to the office, but nothing will happen until at least June 1. Alphabet, the parent company of Google, is scheduled to report its first-quarter earnings after the bell on Tuesday.

The company will have workers return "gradually" to ease anxiety around leaving home, Pichai added. "Not everyone at a site will go back at once," he said. "There will be no one-size-fits-all approach, and the specific guidance will vary from location to location."

Pichai's plan was previously reported by Business Insider.

The latest plan comes as the company tries to mobilize its massive workforce, many of whom have asked leadership about the future of their return to offices amid spending and hiring changes. It comes more than a month after Google was one of the first large companies to recommend employees work from home in early March in order to prevent the coronavirus from spreading. CNBC first reported Alphabet executives' detailed initial planning, which took place weeks before the virus was considered a global pandemic.

"I know that many of you have questions about what a return to the office might look like, and when," Pichai said in his email to employees. "The six counties around Google's headquarters in California have just announced an extension to the stay-at-home order through the end of May, while many other localities around the world are issuing their own guidance."

Pichai went on to say he does not have a specific date for return, however he said, "everyone who is in a recommended or mandatory work-from-home status should assume that will continue until at least June 1, 2020." Pichai noted that workers are still being told they can work from the office if they're in the Asia Pacific region. "Please continue to follow your site-specific guidance," he said.

Even when offices do begin to reopen, workers taking care of family members or who have "special considerations" won't have to return immediately, he noted. They'll have the option to work with their managers on a "flexible" approach, he said.

Pichai said the company has "high level principles" that are guiding the return decisions. "We were one of the first companies to move to WFH, we will be equally careful about our transition back to the office," he wrote.

Upon their return, teams will continue to monitor local conditions and adjust accordingly, leaning on health agencies, medical community and the company's Global and Regional Incident Response Teams that are "constantly evaluating data," Pichai said.

Pichai also said it will continue some remote working and online events even after restrictions are lifted. The pandemic's been an "opportunity to reimagine" how the company works, he said.

"I know that the prospect of returning to the office will produce different emotions for everyone," Pichai said. "Some of us will be eager to return to our familiar workspaces and see colleagues. For others, leaving loved ones and the shelter of our homes may cause anxiety."

Pichai also thanked employees that have continued to come onsite for offices and data centers.

"For those of you currently working onsite to provide critical services to keep our products, offices and data centers running, thank you!" Pichai said. "Your work has made it possible for us to help millions of others. I am grateful for everything our global teams are doing to deliver on our mission under these difficult circumstances."