[10] On March 17, 2020, the Road Atlanta round was forced to be postponed due to the COVID-19 pandemic.
[11] This was the start of a series of postponements and cancellations that lead to a revised schedule being announced on April 7, 2020.
[13] The rounds at Watkins Glen and Lime Rock Park were the final casualties of the outbreak with late cancellations leading to double headers at Virginia International Raceway and Road Atlanta.
[15] Sonoma Raceway gained a second date with the first kicking off the series and the second being moved to August.
This was done at the expensive of the Auto Club Speedway roval which lost its place on the calendar.