From the Wikipedia page 
Mbeya Region is one of Tanzania's 31 administrative regions. It is located in the country's southwest. The regional capital is the city of Mbeya.
In 2016, the town of Tunduma and the districts of Ileje, Mbozi, Momba and Songwe (created from the western part of Chunya District) were split from Mbeya Region to create Songwe Region. Mbeya Region is now bordered to the northwest by Tabora Region, to the northeast by Singida Region, to the east by Iringa Region, to the south by Songwe Region and Malawi, and to the west by Songwe Region. Prior to the creation of Songwe Region, Mbeya Region covered an area of 62,420 square kilometres (24,100 sq mi). It now covers an area of 35,954 square kilometres (13,882 sq mi)