It will be a rematch of their clash in the Australian Open final, won 7-6 6-2 by Paes and Stepanek, who have won four Grand Slam titles together.
The Bryans, winners of 80 doubles titles including 11 Grand Slam crowns, beat the ninth-seeds Aisam-Ul-Haq Qureshi of Pakistan and Jean-Julien Rojer of the Netherlands 6-3 6-4 in their semi-final at the National Tennis Center.
A 12th Grand Slam triumph for the brothers would tie them with Australians John Newcombe and Tony Roche as the most successful doubles combination in the Grand Slams.
India's Paes, who has seven Grand Slam titles, and Stepanek of the Czech Republic advanced past Marcel Granollers and Marc Lopez when the Spanish duo were forced to retire with the first set tied 6-6 because of a left leg injury to Lopez.
The women's doubles final was also set with French Open champions Sara Errani and Roberta Vinci of Italy advancing with a 6-3 6-2 drubbing of Spain's Nuria Llagostera Vives and Maria Jose Martinez Sanchez.
Errani and Vinci will meet the Czech pair of Andrea Hlavackova and Lucie Hradecka in Sunday's final.
Hlavackova and Hradecka defeated Su-Wei Hsieh of Taiwan and Anabel Medina Garrigues of Spain 7-6 6-4 in their semi-final.
- Grand Slam titles