All our mattresses are designed for high performance and come with a 10-year warranty, including custom mattresses. Our mattresses do not have any moving parts, the two major components are the foam and the fabric. The warranty covers any issues with the foam - i.e. sinking, pitting, sagging or any pre-existing defect that is not customer caused. If you notice any visible sagging of more than 1inch, please send us pictures and we will proceed with the replacement of your mattress.