((a)) In this section, the term “engineering or scientific duty” means service performed by an officer—
((1)) that requires an engineering or science degree; and
((2)) that requires a skill designated (under regulations prescribed by the Secretary of Defense for the armed forces, by the Secretary of Commerce for the National Oceanic and Atmospheric Administration, or by the Secretary of Health and Human Services for the Public Health Service) as critical and as a skill in which there is a critical shortage of officers in the uniformed service concerned.
((b)) Under regulations prescribed by the Secretary concerned, an officer of a uniformed service who—
((1)) is entitled to basic pay;
((2)) is below the pay grade of O–7;
((3)) holds a degree in engineering or science from an accredited college or university;
((4)) has been certified by the Secretary concerned as having the technical qualifications for detail to engineering or scientific duty;
((5)) has completed at least three but less than nineteen years of engineering or scientific duty as an officer; and
((6)) executes a written agreement to remain on active duty for detail to engineering or scientific duty for at least one year, but not more than four years;
((c)) An officer who, having entered into a written agreement under subsection (b) and having received all or part of a bonus under this section, does not complete the period of active duty as specified in the agreement shall be subject to the repayment provisions of .