The private sector added just 27,000 jobs in May — the fewest in 9 years — way below the 173,000 economists had been expecting, ADP and Moody's Analytics said on Wednesday.

Why it matters: The data is typically a good barometer of what’s to come in the government’s official jobs report. It comes amid concerns that the stellar job market may finally be slowing down. In a press release, Moody’s chief economist Mark Zandi said, "Job growth is moderating. Labor shortages are impeding job growth, particularly at small companies, and layoffs at brick-and-mortar retailers are hurting."

Go deeper ... Chart: How many jobs the U.S. economy has added each month