Saatva's box foundation serves the same purpose as a traditional box spring: it elevates the mattress to a comfortable height, keeps it from sagging, and prolongs its life. The Saatva foundation works with all of our mattress styles, except for the Saatva HD. We highly recommend you pair our HD mattress with our HD foundation.
While you don't have to purchase a foundation from us if you currently have a box spring that's in good condition, note that Saatva's warranty requires that king and queen mattresses have proper center support. (Learn more about box springs, foundations, and frames here.)