Okla. Stat. tit. 11 § 49-101.2
Any member serving as an active volunteer firefighter who receives annual compensation from the fire department the firefighter is enrolled in as a member of the System for services related to firefighting, other than reimbursement of expenses in excess of five and one-half (5 1/2) times the annual pension benefit paid by the System to a retired volunteer firefighter with twenty (20) years credited service, shall be considered a paid firefighter and must meet the physical and agility requirements pursuant to Section 49-116 of this title to continue as an active member of the System. Credited service earned as a paid firefighter pursuant to this section shall not be considered actual experience as a paid firefighter for purposes of meeting the qualifications of a paid fire chief as provided in Section 29-102 of this title. No fire department of a participating municipality shall employ a volunteer firefighter from another fire department to perform services relating to firefighting for any compensation of any kind.
Okla. Stat. tit. 11, § 49-101.2