| Code | Explanation | From | Through |
|---|---|---|---|
| 1 | Competitive service. See 5 U.S.C. 2102 for definition of the competitive service. | 06/01/1972 | Present |
| 2 | Excepted service. This position is not in the competitive service or in the Senior Executive Service. See 5 U.S.C. 2103 for definition of the excepted service. | 06/01/1972 | Present |
| 3 | SES General. Employee in the SES occupies a general position as defined in 5 U.S.C. 3132(a)(9). | 07/01/1979 | Present |
| 4 | SES Career Reserved. Employee in the SES occupies a career reserved position as defined in 5 U.S.C. 3132(a)(8). | 07/01/1979 | Present |