The National Association of Realtors said Thursday that existing home sales advanced 4.2 percent to an annual rate of 5.18 million units, the highest level since November 2009 when a home-buyer tax credit was expiring.
"Whatever inventory is coming onto the market, buyers are ready to snap it up," said Lawrence Yun, an economist at the NAR.
The increase beat expectations for a rise to a 5 million-unit rate last month.
The housing market is one of the brightest spots in America's economy and is helping counter Washington's decision to raise tax rates and cut government spending this year.
A very accommodative monetary policy by the Federal Reserve, which has held mortgage rates near record lows, is helping to lift the housing market off the floor. Fed Chairman Ben Bernanke, however, gave clear signals on Wednesday that the Fed was on track to start dialing back its stimulus by the end of this year.
In May, the median home sales price increased a whopping 15.4 percent from a year ago to $208,000. That was the biggest year-over-year increase since 2005 and left prices at their highest level since July 2008.
"Prices have recovered quite suddenly and quite spectacularly," Yun said.
With prices rising, more sellers put their properties on the market, lifting the inventory of unsold homes on the market 3.3 percent from April to 2.22 million.
Still, the stock of homes for sale continues to be tight in the market. The May level of inventories represented just 5.1 months' supply at May's sales pace, down from 5.2 in April. Many economists consider 6.0 months to be a healthy balance between supply and demand.