Montagny, who tested last month on the Homestead-Miami Speedway road course, is scheduled to participate in the Open Test on the 2.46-mile, 14-turn Indianapolis Motor Speedway circuit April 30.
The former Formula 1 driver made his American open-wheel debut in the April 2008 Champ Car finale at Long Beach, finishing second to Will Power.
He competed for AFS/Andretti Autosport in August 2009 at Sonoma Raceway (started eighth and finished 20th).
Practice for the Grand Prix of Indianapolis kicks off at 10 a.m. May 8, with the three rounds of qualifications starting at 2 p.m. May 9. The race is scheduled for May 10 (3:30 p.m.).