Block
The district of Samastipur came into existance on 14th Nov. 1972 carved out of the erstwhile Darbhanga district. The present district of Samastipur consists of 4 subdivision. The district has 20 CD block, 01 Nagar Nigam-Samastipur, 04 Nagar Parishad-Rosera, Dalsinghsarai, Tajpur, Shahpur Patori, 03 Nagar Panchayat-Musrigharari, Sarairanjan, Singhiya, 343 panchayats and 1260 revenue villages with district headquarter at Samastipur. Samastipur district is a part of Darbhanga commissionary.
| Sl.No. | Sub-Division | Block |
| 1. | Samastipur | Samastipur |
| 2. | Tajpur | |
| 3. | Morwa | |
| 4. | Khanpur | |
| 5. | Sarairanjan | |
| 6. | Pusa | |
| 7. | Warishnagar | |
| 8. | Kalyanpur | |
| 9. | Rosera | Rosera |
| 10. | Hasanpur | |
| 11. | Bithan | |
| 12. | Shivajinagar | |
| 13. | Singhiya | |
| 14. | Bibhutipur | |
| 15. | Dalsinghsarai | Dalsinghsarai |
| 16. | Ujiyarpur | |
| 17. | Vidyapatinagar | |
| 18. | Patori | Patori |
| 19. | Mohanpur | |
| 20. | Mohiuddin Nagar |