A support structure has a pair of elongate side panels and a pair of end support frame assemblies for maintaining the side panels in a mutually spaced relationship and at an elevation to enable suspension of hanging file folders from upper surfaces of the side panels. Each of the side panels includes a top member having the upper surface, a bottom member spaced apart from the top member, and at least one reinforcing member interconnecting the top and bottom members. Each of the top and bottom members has opposite terminal ends each formed as a connecting member having a vertical slot. Each of the end support frame assemblies includes a pair of support legs configured to extend through the vertical slots of the respective connecting members of the side panels and includes at least one transverse support member having opposite terminal ends configured to be releasably mounted to respective ones of the support legs.