CSAC officials formally made the change on Wednesday, one day after receiving the results of Jones' "B" sample from a failed drug test on July 28. Results confirmed that Jones tested positive for Turinabol, an anabolic steroid.
Jones (22-1) reclaimed the UFC title by knocking out Cormier in the third round. The UFC has not yet announced its immediate plans for the division, now that Jones' victory has been erased.
Jones, 30, has denied knowingly taking a banned substance. Under the UFC's anti-doping program, he faces a maximum four-year suspension. He served a one-year suspension in 2016, after testing positive for two banned anti-estrogenic substances.