The index rose 5.9 percent in May to 101.1, up from 95.5 in April. Annual gains were also strong with monthly and 12-month gains noted in every region of the country.
"The housing market is clearly superior this year compared with the past four years. The latest increase in home contract signings marks 13 consecutive months of year-over-year gains," said NAR Chief Economist Lawrence Yun.
"Actual closings for existing-home sales have been notably higher since the beginning of the year and we're on track to see a 9 to 10 percent improvement in total sales for 2012," Yun said.
The pending sales index is termed a "leading" or "forward-looking" economic indicator because it predicts future home sales."
NAR said the pending home sales index rose 4.8 percent in the Northeast to 82.9 with pending contracts 19.8 percent higher than a year earlier. In the Midwest, pending home sales rose 6.3 percent month-to-month to 98.9, which is 22.1 percent higher than May 2011.
In the South, the index rose 1.1 percent in the month, but at 106.9, the index is 11.9 percent higher than a year earlier. In the West, the index jumped 14.5 percent in May to 108.7, 4.8 percent higher than May 2011.