Jones tested positive for cocaine during an out-of-competition drug test conducted by the Nevada Athletic Commission on Dec. 4, 2014.
Jones fought a month later, defeating Daniel Cormier at UFC 182. His basic purse for the win was listed at $500,000.
He was allowed to compete because cocaine is only banned by the World Anti-Doping Association in competition. The Nevada commission follows WADA's lead.
The UFC said Jones passed all required drug tests following UFC 182 on Jan. 3
The $25,000 will be donated to a substance abuse prevention program.