In Kenya, extra county schools fall in the second tier after national schools. In recent years, cases have emerged where extra county schools perform better than national school. Extra county secondary schools in Nandi county are grouped into three clusters; cluster one(C1), cluster two(C2) and cluster three (C3). Kapsabet Girls High School, Aldai Girls Secondary School, Samoei Boys Secondary School among other schools form cluster one schools in Nandi County.
| S/N | SCHOOL CODE | SCHOOL NAME | TYPE | CLUSTER |
| 1. | 29513101 | Kapsabet Girls High School | Girls | C1 |
| 2. | 29513308 | Our Lady of Victory Girls Kapnyeb | Girls | C1 |
| 3. | 29513310 | Terige Secondary School | Boys | C1 |
| 4. | 29523101 | Kemeloi Boys Secondary School | Boys | C1 |
| 5. | 29523302 | Aldai Girls Secondary School | Girls | C1 |
| 6. | 29523307 | Aic Chebisaas Girls Secondary School | Girls | C1 |
| 7. | 29540104 | Stephen Kositany Girls’ High School | Girls | C1 |
| 8. | 29540201 | Kurgung Secondary School | Boys | C1 |
| 9. | 29540202 | Laboret Boys High School | Boys | C1 |
| 10. | 29541201 | Samoei Boys Secondary School | Boys | C1 |
| 11. | 29542101 | Meteitei Boys Secondary School | Boys | C1 |
| 12. | 29579701 | Lelmokwo High School | Boys | C1 |
| 13. | 29579702 | Itigo Girls Secondary School | Girls | C1 |
| 14. | 29513305 | Kilibwoni High School | Boys | C2 |
| 15. | 29523103 | Serem Secondary School | Boys | C2 |
| 16. | 29523308 | Kapkolei Girls Secondary School | Girls | C2 |
| 17. | 29540102 | Cheptil Secondary School | Mixed | C2 |
| 18. | 29540205 | Ndalat Gaa Girls’ Secondary School | Girls | C2 |
| 19. | 29513204 | Holy Rosary Girls’ Secondary School | Girls | C3 |
| 20. | 29540204 | Tulwo Girls High School | Girls | C3 |
| 21. | 29541101 | Lelwak Secondary School | Boys | C3 |
| 22. | 29541202 | Our Lady Of Peace Girls’ Secondary School | Girls | C3 |
| 23. | 29542102 | St.Mary’s Tach Asis Girls Secondary School | Girls | C3 |