37 U.S.C. § 415: Uniform allowance: officers; initial allowance

upon first reporting for active duty (other than for training) for a period of more than 90 days; upon completing at least 14 days of active duty as a member of a reserve component; upon completing 14 periods, each of which was of at least two hours’ duration, of inactive-duty training as a member of the Ready Reserve; or upon reporting for the first period of active duty required by section 2121(c) of title 10 as a member of the Armed Forces Health Professions Scholarship program. An officer who has received an initial uniform reimbursement or allowance under any other law is not entitled to an initial allowance under subsection (a). on active duty or on inactive duty training status; and required by directive of the Surgeon General to wear a uniform.