The fourth year of IROC competition took place over three weekends in 1976 and 1977. IROC IV saw the use of the Chevrolet Camaro in all races, and the schedule was held over in its entirety from IROC III. A. J. Foyt won the championship without winning a race for the second year in a row, and took home $50,000 for his efforts.
The roster of drivers and final points standings were as follows:
| Position | Driver | Winnings | Series |
|---|---|---|---|
| 1 | A. J. Foyt | $50,000 | USAC Champ Car |
| 2 | Cale Yarborough | $25,000 | NASCAR Winston Cup |
| 3 | Bobby Unser | $23,000 | USAC Champ Car |
| 4 | Johnny Rutherford | $20,000 | USAC Champ Car |
| 5 | Buddy Baker | $18,000 | NASCAR Winston Cup |
| 6 | Richard Petty | $15,000 | NASCAR Winston Cup |
| 7 | Al Holbert | $13,000 | IMSA Camel GT |
| 8 | Al Unser | $10,500 | USAC Champ Car |
| 9 | David Pearson1 | $10,500 | NASCAR Winston Cup |
| 10 | Jody Scheckter | $5,000 | Formula One |
| 11 | Gordon Johncock | $5,000 | USAC Champ Car |
| 12 | James Hunt2 | $5,000 | Formula One |