37 U.S.C. § 302g

(a) Special Pay Authorized .— An officer of a reserve component of the armed forces described in subsection (b) who executes a written agreement under which the officer agrees to serve in the Selected Reserve of an armed force for a period of not less than one year nor more than three years, beginning on the date the officer accepts the award of special pay under this section, may be paid special pay at an annual rate not to exceed $25,000. (b) Eligible Officers .— An officer referred to in subsection (a) is an officer in a health care profession who is qualified in a specialty designated by regulations as a critically short wartime specialty. (c) Time for Payment .— Special pay under this section shall be paid annually at the beginning of each twelve-month period for which the officer has agreed to serve. (d) Repayment .— An officer who does not complete the period of service in the Selected Reserve specified in the agreement entered into under subsection (a) shall be subject to the repayment provisions of section 303a(e) of this title . (e) Termination of Agreement Authority .— No agreement under this section may be entered into after December 31, 2018 .