And it's a sign that employers are having a harder time filling open positions, which means they'll likely have to pay more when they make their next hire.
"Despite the slowdown in payroll gains in August, labor market conditions continue to tighten, which should eventually generate a pick-up in wage growth later this year," according to Steve Murphy, an economist at Capital Economics.
Employers posted 5.9 million job openings in July, a rate of 3.9 percent, according to the Job Openings and Labor Turnover Summary (JOLTS) report. That compares to 5.62 million job openings in June, according to Thomson Reuters.
The survey, which tracks the number of open positions along with how many workers have been hired, fired or just up and quit their jobs, gets much less attention than the high-profile payroll and jobless rate data that comes out on the first Friday of every month.
Lately, JOLTS has been getting more attention — in part, because it's one of the data points closely watched by Federal Reserve Chair Janet Yellen. The central bank is keeping a close eye on the job market as a bellwether for the strength of the recovery as it decides how soon to raise interest rates.
The latest report showed that the hiring rate, which also has been rising steadily as the job market has recovered since the wave of layoffs of the Great Recession, flattened out at 3.6 percent, or 5.2 million new hires in July.
That measure is approaching the 4.0 percent level seen in November of 2006, before the recession hit.
With the number of openings and hiring rate rising this year, so has the pace of workers who decide to up and quit their jobs.
That so-called "quits rate" is one measure the Fed keeps a close eye on; economists say it's a good gauge of workers' confidence in the job market. When more workers decide to quit, it's a sign they see better job opportunities elsewhere.
Often, those job quitters are rewarded for making a move with a bigger paycheck, according to a separate monthly report from Atlanta Federal Reserve. That data tracks wage gains, comparing those who have switched jobs and those who stick it out with their current employer.
According to the latest monthly data, "job switchers" saw an average pay bump of 4.2 percent, while "job stayers" saw their paychecks rise by 3.0 percent.