D.C. Code § 38-2061.02

Any teacher who, on or after June 27, 1960, retires pursuant to part A of subchapter II of this chapter shall be entitled to have included in the years of service creditable to him for retirement purposes any period of authorized leave of absence which was taken by him without pay, and for educational purposes; except that credit for any such period shall be conditioned upon payment by such teacher to the Custodian of Retirement Funds (as defined in § 1-702(6)), for deposit in the District of Columbia Teachers’ Retirement Fund established by § 1-713(a), of a sum equal to the accumulated contributions which would have been credited to his individual account if he had remained on active duty in the public schools of the District of Columbia during any such period plus interest computed in accordance with § 38-2023.14(b); provided, that in order to receive such retirement credit a teacher must produce evidence satisfactory to the Superintendent of Schools of the District of Columbia that the authorized leave of absence without pay was taken for educational purposes.