NASCAR announced a significant competition procedure change on Thursday that will take effect immediately, beginning with this weekend’s national series races at Iowa Speedway. The change will be in effect starting with the ARCA Menards Series event on Friday before carrying over to Saturday’s NASCAR O’Reilly Auto Parts Series race and Sunday’s NASCAR Cup Series Iowa Corn 350. pic.twitter.com/cNmpyfKhjC — NASCAR (@NASCAR) August 6, 2026When the field returns to the start-finish line under yellow, the race leader will receive the green-and-white checkered flag to officially end the stage. The NASCAR Cup Series headlines the Iowa Speedway schedule with Sunday’s Iowa Corn 350, while the NASCAR O’Reilly Auto Parts Series competes Saturday. The new procedure will be in effect throughout the weekend as NASCAR debuts the rule for the first time.