5 U.S.C. § 5365

(a) The Office of Personnel Management shall prescribe regulations to carry out the purpose of this subchapter. (b) Under such regulations, the Office may provide for the application of all or portions of the provisions of this subchapter (subject to any conditions or limitations the Office may establish)— (1) to any individual reduced to a grade of a covered pay schedule from a position not subject to this subchapter; (2) to individuals to whom such provisions do not otherwise apply; and (3) to situations the application to which is justified for purposes of carrying out the mission of the agency or agencies involved. Individuals with respect to whom authority under paragraph (2) may be exercised include individuals who are moved without a break in service of more than 3 days from employment in nonappropriated fund instrumentalities of the Department of Defense or the Coast Guard described in section 2105(c) to employment in the Department of Defense or the Coast Guard, respectively, that is not described in section 2105(c).