The housing market continues to be in a state of transition. While industry watchers expected existing-home sales to jump in May, the numbers told a different story today.

According to data released Tuesday by the National Association of Realtors (NAR), existing home sales dipped 2.2% in May to a seasonally adjusted pace of 5.7 million. While that does qualify as a drop from April, which was the final month to take advantage of the federal housing tax credit, the figure still stands 19.2% above May 2009.

“We are witnessing the ongoing effects of the home buyer tax credit, which we’ll also see in June real estate closings,” said Lawrence Yun, NAR’s chief economist. Buyers must settle on their homes by June 30 to take advantage of the credit.

In terms of much-watched home values, the NAR reported a national median existing home price of $179,600 in May, which represents a 2.7% annual gain.

In other home price news, the Federal Housing Finance Agency said today that its home price index increased 0.8% in April on a monthly basis.

“Federal tax credits for first-time home buyers and existing homeowners contributed to the strength of house prices in April,” the FHFA statement said. “The tax credits, which required that purchase contracts be signed by the end of April, increased sales volumes dramatically during the month and, in some cases, likely increased bidding prices.”

But many homeowners continue to struggle with soft housing values. Compared to the same month one year ago, the index is down 1.5%.

In the past year, the Pacific region has shown the most price growth, with an index gain of 3.2%. All other regions showed annual declines, with the exception of West South Central, which includes Oklahoma, Arkansas, Texas, and Louisiana.

The weakest spot remains the Mountain region, with a 5.4% yearly decline. This Census region contains two of the states that have been hardest hit by the housing crisis—Nevada and Arizona—as well as Montana, Idaho, Wyoming, Utah, Colorado, and New Mexico.

Alison Rice is senior editor, online, at BUILDER magazine.