2 U.S. Code § 1931 - Additional compensation for employees with specialty assignments and proficiencies
The Chief of the Capitol Police may establish and determine, from time to time, positions in salary classes of employees of the Capitol Police to be designated as employees with specialty assignments or proficiencies, based on the experience, education, training, or other appropriate factors required to carry out the duties of such employees.
The additional compensation authorized by this subsection shall be paid to an employee in a manner determined by the Chief or his designee except when the employee ceases to be assigned to the specialty assignment or ceases to maintain the required proficiency. The loss of such additional compensation shall not constitute an adverse action for any purpose.
Any determination under section  (a) shall not be appealable or reviewable in any manner.
 So in original. Probably should be “subsection”.