This is the highest rate since May 2008.
"These numbers are in line with our recent builder surveys, which indicate that more consumers are getting off the fence and coming back into the marketplace," said Kevin Kelly, chairman of the National Association of Home Builders (NAHB).
"This increase is a welcome sign after a slow start to 2014," said NAHB chief economist David Crowe. "As job creation continues, we can expect further release of pent-up demand and continued gradual growth in the housing recovery."
Regionally, new-home sales were up across the board. Sales rose 54.5% in the Northeast, 34% in the West, 14.2% in the South and 1.4% in the Midwest.
The inventory of new homes for sale held steady at 189,000 units in May. This is a 4.5-month supply at the current sales pace.