That is a great question!

Yes and no, here is why.

Need? No. Required for their warranty? Yes.

No mattress "needs" a box spring these days. All mattresses can easily sit perfectly fine on a slatted or breathable base. However, most companies will try to get you to buy their box spring by stipulating their warranty can be voided if you don't put it on the required box spring. They do this to insure it is supported properly. Without knowing what your specific support situation is, they can only warranty it if they know what it is sitting on definitively.

Simmons foundations are "limited deflection" units…this means they have no give (as does a true box spring) So, you need a foundation or platform bed with proper support. Foundations are purely cosmetic to elevate the mattress, most often used with traditional headboard/footboard furniture. Platform beds have slats. I prefer adding a "bunkie board" to platform beds. A bunkie board is a 1-1 1/2" solid, upholstered unit. It just adds even more solid support to a platform bed, unless the platform bed has a sold surface, no slats.

Hi, The purpose of the boxspring and frame is to hold the mattress up at a convenient height. Still, the mattress has to be supported by something. The floor is a great place to put your mattress. The benefit from the exercise involved in getting up and down can be felt within two weeks. Platform beds, adjustable bed bases are a couple of other things that you can use. The warranty may be compromised, especially if using an old boxspring. Except for that, the warranty remains in effect. The over-all problem with warranties is in getting the factories to honor them...something that is difficult, even with a matching boxspring. The mattress you've chosen is a good one. That same mattress is available at any Simmons dealer. And while the model names will change from dealer to dealer, the specifications are the same. It's the starting model of the World Class Series. It's called Annapolis Place at our store.