D.C. Mun. Regs. tit. 17, § 7515
7515.1 A supervised practice form shall be submitted two (2) weeks prior to commencement of supervised practice. A supervised practice form may only be issued to an applicant one (1) time. An applicant may practice massage therapy while working under a supervised practice form for no more than ninety (90) days, and may practice at multiple locations at the discretion of the supervisor(s).
7515.2 A supervisor may supervise no more than three (3) applicants at any one time.
SOURCE: Final Rulemaking published at 54 DCR 8933 (September 14, 2007).