The iPhone-maker had intended to bring workers in for three days a week from September but this had now been put back until at least October, the news agency said.
Sources told Bloomberg employees would be given at least a month's notice before having to return.
BBC News has asked Apple for comment.
Apple's plans for a return to the office had been met with firm opposition from some staff.
In June, chief executive Tim Cook sent a company-wide memo telling workers they would have to return to their desks.