The number of college-educated workers retiring far outpaces the number of young people entering the workforce with similar levels of education, creating a national skills shortage, according to a new report from Georgetown University’s Center on Education and the Workforce.

The report, released Tuesday, found that 18.4 million people with postsecondary credentials are expected to leave the workforce between 2024 and 2032, and only 13.8 million younger workers are expected to enter the workforce with equivalent education. Meanwhile, the country is projected to add 685,000 new jobs that require postsecondary credentials over that same period. The report predicted the U.S. economy will need an additional 5.25 million workers with college credentials or training through 2032, and 4.5 million of those workers will need a bachelor’s degree or higher.

According to the report, 171 different occupations are headed for skills shortages, but certain job types are projected to be especially hard hit, including accountants, attorneys, construction workers, doctors, engineers, managers, nurses, teachers and truck drivers.

The report also identified occupations expecting sizable workforce shortages that fill important social and economic needs. For example, the report projected future shortfalls of 611,000 teachers and 362,000 nurse practitioners.

The report emphasized the importance of not just bringing more people into the workforce but ensuring more people pursue postsecondary credentials and training. It noted that if the U.S. could increase its labor force participation rate back to its peak of 67.3 percent in 2000, and maintain a 4.1 percent unemployment rate as it did then, the workforce could expand by 12 million workers by 2032, but it still wouldn’t be enough; 52 percent of those workers are projected to have no education beyond high school.

Nicole Smith, lead author and chief economist at Georgetown CEW, said in a news release that workforce shortfalls can’t be fixed “without massive and immediate increases in educational attainment.”