American Express and BNY Mellon plan to call employees back to the office in March.

With New York’s coronavirus cases declining, some Wall Street firms are recycling their favorite human resources message: back to the office, for real this time.

BNY Mellon, a global bank with nearly 50,000 employees, including 5,400 in New York, told all its staff in a memo Thursday that their return-to-office date would be March 7. But the firm has broken from many of its industry peers in adopting a more flexible approach to reopening its workplace.

American Express also announced on Thursday that it would require workers to return to office next month under a hybrid model the company introduced last year.

At BNY Mellon, managers will be permitted to determine which days employees are required to be in the office. Employees will also have the option to work anywhere in the world for two weeks each year.

“It gives our teams the freedom and responsibility to determine the mix of remote and in-office experiences that will enable them to perform at their best,” Thomas P. Gibbons, the firm’s chief executive, wrote in the memo.

BNY Mellon told employees last summer that they had to be fully vaccinated against the coronavirus to enter its offices. It did not share how it would handle employees who refused to be vaccinated.

American Express told its employees that they would be encouraged to return to the office starting March 1, followed by a broader return on March 15. Last year, the company announced a flexible working model called Amex Flex, where team leaders can decide whether their employees work mostly on-site, hybrid or remotely.

Starting next month, all eligible American Express employees have to be fully vaccinated and have gotten their booster shots to enter the company’s U.S. offices. Employees who refuse to get vaccinated or to disclose their vaccination status have to apply for permission to work virtually.

Financial firms have been among the most eager white-collar employers to see workers report back to their desks. Goldman Sachs and JPMorgan Chase both asked workers to return to the office on Tuesday, while Citigroup told employees in the New York metropolitan area that they will need to come back starting Monday for at least two days a week. Jefferies, a New York investment bank, and the Swiss lender UBS have both embraced hybrid working.

But many employers, including those in finance, conceded a new degree of uncertainty in their return-to-office plans amid the spread of the highly infectious Omicron variant of the coronavirus. A January survey from the Partnership for New York City, a business advocacy group, found that 22 percent of 187 major Manhattan employers could not estimate when their offices would reach even half capacity.

And for some employers, like BNY Mellon, that uncertainty has given way to new forms of flexibility.

“We are helping support the future of the work force with a flexible hybrid approach,” Jolen Anderson, the head of BNY Mellon’s human resources, said of the company’s new hybrid model. “That will set us apart from peers.”