The race was organized by the Stéphane Ratel Organisation (SRO).

The second annual California 8 Hours is the fourth and final round of the 2018 Intercontinental GT Challenge.

42 Strakka Racing Mercedes-AMG GT that had finished eighth overall, and first in GT3 Pro-Am, was disqualified under after driver Nick Leventis was found in violation of FIA doping regulations.

Leventis' urine sample was taken to the Sports Medicine Research & Testing Laboratory at the University of Utah in Salt Lake City, Utah, where it tested positive for anastrozole (an exogenous aromatase inhibitor, prohibited under S4.1 of the FIA Anti-Doping Code), drostanolone and related metabolite 2α-methyl-5α-androstan-3α-ol-17-one, which are exogenous anabolic 3 androgenic steroids, prohibited under S1.1.a of the FIA Anti-Doping Code).

The results were altered on 26 June 2019 after an official report of the positive test.