Jon Jones won't be stepping into the Octagon until next year ... 'cause the UFC fighter was just slapped with a year suspension resulting from a failed drug test before UFC 200.
USADA announced the ruling Monday morning ... saying they "determined that Jones should receive the maximum one-year period of ineligibility for his anti-doping violation."
The 29-year-old superstar tested positive for clomiphene and letrozole -- anti-estrogen agents that are often used after a cycle of steroids to counter to the negative side affects.
Traces of the drugs were found in a urine test from June 16, 2016 -- an out of competition test leading up to UFC 200.
Jones was set to fight Daniel Cormier at UFC 200 on July 9th ... but he was pulled from the card 3 days before the event due to the failed test.
It's not all bad news for Jones. The suspension was backdated to the day the failed test was made public ... meaning Jones is eligible to return July 6th, 2017.
Jones still faces possible punishment from the Nevada State Athletic Commission.