There will be two types of markets when all-day breakfast rolls out. One market will offer McMuffin sandwiches and no biscuits while the other will offer biscuits and not McMuffins. Both will offer platters, sausage burritos and sides.
Dow Jones initially reported the news.
The move, which would keep regular menu items intact, comes as the fast-food company's new leadership has promised to be more agile in response to consumer demand, including all-day breakfast. Sources had previously told CNBC the menu change would happen as early as October, after some restaurants began testing the new menu several months ago.
McDonald's reported same-store sales below analyst estimates in a July quarterly earnings report, indicating that fewer diners were visiting the restaurants, despite beating earnings and revenues estimates. The all-day breakfast move is one of several changes under CEO Steve Easterbrook, who said in the earnings report he is trying to modernize the company.
—CNBC's Katie Little contributed to this report