A hospital bed includes a sleep deck having an upper portion, a middle portion, and a lower portion each defining a support surface and an underbody that defines a notch. An opening is defined by and extends through the upper portion. A space is defined between the upper portion and the middle portion. A mattress is disposed on the sleep deck. An outer mattress shell encases the mattress and includes a fold defined by a weld. A mattress retention assembly is coupled to the outer mattress shell. The mattress retention assembly includes at least one of a first magnet and a second magnet selectively coupling the mattress to the sleep deck, a portion of the mattress retention assembly extends between the outer mattress shell and the sleep deck, an affixing member disposed on the outer mattress shell, and a retention ridge extending through the sleep deck.