The deal is in effect until 2024, but won't officially kick off until the 2015 season, when NBC and Fox will begin sharing in earnest. The two networks are likely to air some of the races on the NBC Sports network and Fox Sports 1 (which replaces Speed TV), respectively.
Financial details have not been revealed for the NBC deal yet. Fox and NASCAR's tie-up, which was renewed last fall, was valued at $2.4 billion, and gets the News Corp-owned network broadcast rights for the Daytona 500, 12 Sprint Cup races, practicing and qualifying, and the Camping World Truck Series.
The network shift will see ABC/ESPN and Turner Broadcasting end their NASCAR programming with the 2014 season.