I ordered a replacement mattress from the below: The Foam Factory, Mattresses, Conventional Foam The original mattress was a little lumpy but if you have an exped over the top of the old foam you should be fine. The cost of the best foam, Dacron wrapped and with a new striped cover was just under $300 shipped. You can take the mattress cover off and wash it. Check the foam and see it there are any hard spots. Mine had two letters, onn on each side, F which I assumed was firm and the other was S for soft. The S side was definitely more comfortable.