Okla. Admin. Code § 715:10-15-21
A disabled retiree who returns to Oklahoma public school employment at an annual salary equal to or greater than the annual salary received at the time of disability shall again become a member of TRS. Disability retirement payments shall be suspended until the member has qualified to be restored to active service. Upon completion of six (6) months of membership service, the member shall be considered as having met the requirements to be restored to active service. At such time, disability retirement shall be terminated and the unused portion of the accumulated contributions shall be re-established with TRS. If the member again retires under a regular retirement allowance, eligibility to receive a monthly retirement allowance shall be based on total years of creditable service (see OAC 715:10-17-5 ).
Okla. Admin. Code § 715:10-15-21