A typical mattress warranty lasts 10 years, and guarantees that the manufacturer will repair or replace any defective mattress as long as the defect is covered by the warranty. Sagging is one potential defect often covered by mattress warranties, and is commonly covered for indentations ranging between a half-inch and one-and-a-half inches in depth.
It’s important to review the warranty terms before purchasing your mattress, with special consideration to whether the coverage is nonprorated and prorated.
Nonprorated coverage means the manufacturer will cover all repair and replacement costs, less the cost of shipping. Prorated coverage often kicks in after the first 10 years of a warranty, and means the manufacturer will cover only a percentage of the full repair and replacement costs, with the remainder being charged to the customer. Learn more in our Guide to Understanding Mattress Warranties.