The Standard & Poor's/Case-Shiller index, a key measure of home prices, hit its lowest level in nearly a decade in January.
Home prices are down about a third from their peak in the summer of 2006.
The new figures are the latest indication the housing market has yet to turn around despite some improvement in the economy and a somewhat stronger job market.
Washington has tried several measures to help get housing going again. But many analysts say it will take years before the excesses from the bubble in home prices are worked off.