Kolasib District was created in the year 1998, and officially inaugurated in 10.09.1998. Prior to this, it was administered under a vast District of Aizawl District as Kolasib Sub-Division. After carving out Kolasib District, the District has 2 (two) Sub-Divisions, i.e., SDO(C), Vairengte (15.8.2001) and SDO(C), Kawnpui (14.12.2002) and SDC Office, Bairabi which is administered under the DC Office, Kolasib. The District also have 2 (two) R.D. Blocks, viz. Thingdawl RD Block (includes some part of Tlangnuam RD Block) and Bilkhawthlir RD Block . The 2 (two) R.D. Blocks cover the whole district.