The 2026 Quaker State 400 was a NASCAR Cup Series race held on July 12 and 13, 2026, at Atlanta Motor Speedway in Hampton, Georgia. Contested over 263 laps on the 1.54-mile-long (2.48 km) asphalt quad-oval intermediate speedway, extended from the original 260 laps due to a overtime finish, it was the 20th race of the 2026 NASCAR Cup Series season, as well as the third race of the 2026 NASCAR In-Season Challenge.