An interior assembly for a load center includes a base member disposed at or about a panel member of the load center housing, a first bus bar assembly disposed on the base member, and a first insulating member overlaying the first bus bar assembly and being coupled to the base member. A first portion of the first insulating member receives circuit breakers of the load center, and a second portion receives a second bus bar assembly. A second insulating member overlays the second bus bar assembly and is coupled to the second portion of the first insulating member. A neutral bus bar is coupled to the second insulating member. A fastening mechanism fastens the interior assembly to the panel member. The base member, first and second bus bar assemblies, first and second insulating members, and neutral bus bar are secured together without the use of separate fasteners.