Private sector employers added 237,000 jobs in June, the biggest increase in six months, ADP reported Wednesday.
May's job gains were also revised upward from 201,000 to 203,000 in the latest report, which is jointly developed with Moody's Analytics.
"The U.S. job machine remains in high gear," said Mark Zandi, chief economist for Moody's Analytics. "The current robust pace of job growth is double that needed to absorb the growth in the working age population."
The strongest growth came in small businesses, as companies with fewer than 50 employees added 120,000 employees for the month. Companies with 50 to 499 employees added 86,000 jobs. Companies with more than 500 employees added 32,000 jobs in June.
"Small businesses continue to lead the way adding over half of the total jobs this month," said Carlos Rodriguez, president and chief executive officer of ADP.