The eight-hour event is moving from Laguna Seca to the 2.61-mile road course at the Indianapolis Motor Speedway used for the United States Grand Prix in 2000-07 and by IndyCar since 2014.
It will take place on October 4 and will slot in between the rounds at Suzuka and Kyalami respectively in the five-event IGTC schedule, which also incorporates the long-established Spa 24 Hours and Bathurst 12 Hours GT3 enduros.
IGTC boss Stephane Ratel said: "We have three very successful events as part of the IGTC and are very hopeful for our revival of the historic Kyalami 9 Hours in November.
"Our only problem has been America and this year at Laguna Seca [in March] we had a poor grid and a poor crowd.
"The championship is known for visiting historical events and iconic circuits, and with Indianapolis we are undoubtedly dealing with the latter."
He stated that Greg Gill, president of his organisation's North America arm, had been "shopping around for a venue where IMSA doesn't go".
2020 Intercontinental GT Challenge calendar:
|February 1-2||Bathurst 12 Hours|
|July 23-26||Spa 24 Hours|
|August 22-23||Suzuka 10 Hours|
|October 3-4||Indianapolis 8 Hours|
|November 21-22||Kyalami 9 Hours|