JPMorgan Chase & Co. became the first major U.S. bank to mandate a return to offices for its entire U.S. workforce as soon as July.

The lender’s top decision-making body, led by Chief Executive Officer Jamie Dimon, said in a memo to staff Tuesday that it “would fully expect that by early July, all U.S.-based employees will be in the office on a consistent rotational schedule.”

Rotations will be subject to a 50% occupancy cap, until U.S. authorities revise their social distancing guidelines, the memo said. It advised workers that “with this timeframe in mind you should start making any needed arrangements to help with your successful return.”

Industry leaders have been girding for a return to offices since the earliest months of the pandemic last year. Dimon, who’s been going into the office since June, said in September that he sees economic and social damage from a longer stretch of working-from-home. Goldman Sachs Group Inc. CEO David Solomon earlier this year labeled the arrangement an “aberration” that needs to be fixed.

”It was either going to be a big bang, or people easing in,” Sandy Warner, the bank’s former chairman, said of the development. “This is the big bang.”

Prospects for returning to offices have gotten clearer in recent weeks as the vaccines have proliferated across the U.S., with enough shots given to cover about 36% of the population. Citigroup Inc. has said it will start inviting more workers into the office beginning in July, while Wells Fargo & Co. said it hopes for a “more normal operating model” in September. Summer interns at JPMorgan and Goldman will also be able to work from the offices.

In New York, the percentage of workers that have returned to the office has slowly ticked up, though only 15.8% of employees were back as of April 21, according to data compiled by Kastle Systems.

“We firmly believe that working together in person is important for our culture, clients, businesses and teams, and we know that you’ll do your part to make it a positive experience that reflects our company at its best,” the firm’s leaders wrote in the memo.

JPMorgan also said that it while it would “strongly encourage” staff to get vaccinated, a vaccination isn’t required be able to return to the office currently, according to the memo.

The lender will open its U.S. offices to all employees on Monday, May 17—also subject to the occupancy limit, it said. Branches and offices outside of the U.S. will continue to follow established processes.

Dimon is still preparing for an environment where the trend for remote working outlasts the pandemic. He said earlier this month that he expects the bank’s need for real estate to drop significantly, requiring some 60 seats for every 100 employees as some staff work under a hybrid model.

—With assistance from Jenny Surane and Max Abelson.

This article was provided by Bloomberg News.