Abstract: A mattress having a foam core is provided. The foam core may include a channel along two or more sides of the foam core. Spring coils in the channel(s) provide increased localized support proximal the outer edge of the mattress. The spring coils may be conventional spring coils or individually pocketed spring coils. In certain alternatives, the spring coils may be replaced by foam different than the foam core; such difference may include foams having a higher indentation force deflection (IFD) rating. The mattress may have a foam core that is provided with an undercut filled with a foam insert where a higher IFD foam is provided in the undercut.