Abstract: An improved mattress foundation particularly suited for use with foam mattresses to provide proper support for the mattress and to duplicate the feel of box springs. The mattress foundation utilizes an upper and lower frame assembly separated by a flexible, resilient material, which may be in the form of blocks, strips or slabs of flexible, resilient material, with the upper frame assembly preferably being somewhat flexible so as to be capable of deforming from its normal planar condition when subjected to more concentrated loads. The material separating the upper and lower frame assemblies are selected to have a resilience which will support the weight of one or two persons while distributed over the mattress foundation without substantial deflection, but which will deflect significantly when subjected to an individual's weight in more concentrated form, such as occurs when an individual sits on the edge of a bed or is getting into or out of the bed.