The U.S. economy added 173,000 private, non-farm jobs in May, according to a monthly employment report released this morning by payroll-management firm ADP and its partner Moody’s Analytics. The seasonally adjusted number, which fell short of analyst expectations, is a slight increase from April's upward-revised gain of 166,000 payroll positions but is down by 11 percent on a year-over-year basis.

More than 40 percent of May's payroll gains (76,000 jobs) were associated with small businesses that employ fewer than 50 people. That figure is evenly split between companies with fewer than 20 employees and those with 20 to 49 employees.

Despite losses in sectors including energy and manufacturing, the growth in the job market remained fairly healthy, strong, and broad-based in May, Mark Zandi, chief economist for Moody’s Analytics, said in a conference call this morning. Though May's gains represent a dip below the 200,000-job mark for the third time this year, Zandi said, it is still premature to conclude it to be a persistent slowdown.

However, he adds: "We should expect at some point, if not now, a persistent slowing in job creation, in a large part because the economy is close to full employment. In that case, we are going to see job growth slow to be more consistent with the growth of the working-age population, which is no more than 100,000 [jobs] a month, and is going to continue to slow, given the aging and retiring of baby boomers."

The construction sector added 13,000 jobs in May, in line with the April result. After shedding 10,000 jobs in April, manufacturing lost 3,000 jobs in May, the fourth-straight month of payroll contraction for that sector in 2016. The professional and business services category, which includes architecture and engineering firms, added 43,000 jobs in May, building on April’s upward-revised addition of 38,000 positions.

Analysts use the ADP report to forecast the results of the monthly Bureau of Labor Statistics (BLS) Employment Situation Summary. Zandi estimates that May's BLS numbers, which will be released tomorrow, should show the addition of about 160,000 jobs to the U.S. economy. The BLS report will offer more details about job growth in the architecture, engineering, and construction sectors.