America had a near-record number of job openings in March, around 5.75 million according to the Labor Department. That’s slightly below the all-time high of 5.78 million openings set in July 2015. Many experts attribute the phenomenon to the job skills gap. “Employers are having a tougher time finding qualified workers,” Peter Boockvar, chief market analyst at the Lindsey Group, told CNN Money.  

The number of job openings has increased for five straight months, beginning in November. Prior to the Great Recession, in 2007, job openings averaged 4.5 million a month. In 2015, there was an average of 5.3 million openings per month.

The job skills gap explains why there are still high levels of part-time workers and underemployment. It also explains why so many Americans are dissatisfied with the economy, since wages haven’t increased much overall during the economic recovery since the recession.

Just under one-third of small businesses reported in April that they haven’t been able to fill open positions, according to a survey by small-business trade group NFIB. It’s not just unprepared workers causing the skills gap, however. Many employers are experiencing a significant gap between expectations and reality, experts say, and tend to look only for candidates who require little to no training upon hire, an ineffective strategy in the strong job market the country is currently experiencing.

The U.S. government has been working to bridge the skills gap, with President Obama pledging $175 million in grants toward apprenticeship programs last year. It’s the highest ever federal commitment to addressing the skills gap issue.