An adjustable mattress includes a body portion and an extension portion. The body portion includes a first plurality of spaced-apart fingers extending outwardly from at least one edge thereof. The extension portion includes a second plurality of spaced-apart fingers extending outwardly therefrom. The first plurality of fingers are configured for inter-fit engagement with the second plurality of fingers. The extension portion is movable relative to the body portion to vary a degree of inter-fit engagement of the fingers between a first position, wherein the adjustable mattress defines a first dimension, and a second position, wherein the adjustable mattress defines a second dimension.