According to the nationwide index, housing values declined just over 4 percent in the first quarter of 2011. It fell just under 4 percent in the last three months of 2010.
Prices in a dozen markets have reached their lowest points since the housing crisis began. The 12 cities now at their lowest levels in nearly four years are: Atlanta, Charlotte, Chicago, Cleveland, Detroit, Las Vegas, Miami, Minneapolis, New York, Phoenix, Portland, Ore., and Tampa.
In Las Vegas, property values fell 12 percent in the first quarter.
The reasons for the drop include weak demand and more foreclosures hitting the market.
Coastal areas, such as San Francisco, San Diego, Los Angeles, Washington and Boston, have fared comparatively better in the past two years. They have been aided by healthy local economies and low unemployment, desirable city centers and limited space for new housing.
In Los Angeles, property values fell .3 percent in the first quarter.
Experts say it's a buyers and sellers market. Inventory is low, with properties getting multiple offers. "We're seeing everything selling, in all price ranges," said Ed Afsharia of Podley Properties. "The high end may not be going as fast as the mid range."
The Associated Press contributed to this story.