This subchapter applies to—

1. (a) Civilian officers and employees of—

   1. (1) Executive departments as defined in 5 U.S.C. 101;
   2. (2) Independent establishments as defined in 5 U.S.C. 104;
   3. (3) Government corporations subject to 31 U.S.C. chapter 91.;
   4. (4) The Library of Congress;
   5. (5) The Government Publishing Office (GPO); and
   6. (6) The government of the District of Columbia; and
2. (b) Commissioned officers of the National Oceanic and Atmospheric Administration.