In this chapter, the binary group search optimization algorithm (BGSO) is proposed to tackle with optimal network reconfiguration problem in distribution systems. Here, total loss minimization is considered as the objective which is solved subject to system radial operation and power flow constraints. Here, the basics of GSO algorithm is presented first and then, necessary modification for developing BGSO is discussed. The main part of this chapter deals with a source code, which expresses step by step implementation of BGSO method to optimal network reconfiguration problem. Needless to emphasize that the BGSO and associated source code presented in this chapter is a general engine that can be easily adjusted to any optimization problem with binary variables. In addition, the source code associated with the developed forward-backward sweep-based load flow study is also provided. The simulation studies are performed on different distribution networks to examine the scheme at various conditions and problem complexities. Comprehensive simulation studies conducted in this chapter verifies effectiveness of the BGSO and developed source code for solving optimal distribution network reconfiguration problem.