((a)) ** .—** The Secretary may designate a limited number of officers of the Coast Guard as having particular expertise in—
((1)) military justice; or
((2)) healthcare.
((b)) ** .—** An individual designated under this section—
((1)) shall not be included on the active duty promotion list;
((2)) shall be promoted under section 2126; and
((3)) may not be promoted to a grade higher than captain.