Middle-skill jobs, which require education beyond high school but not a four-year degree, make up the largest part of the labor market in the United States and in each of the 50 states.

However, according to the National Skills Coalition's "Forgotten Middle-Skill Jobs: State by State" key industries in America are all too often unable to find enough sufficiently trained workers to fill these jobs.

A new Pew Report “Middle-skills” STEM workers are particularly likely to have had additional training" has found that science, technology, engineering, and math (STEM) workers are more likely than non-STEM workers to have completed a vocational or technical training, a certificate, or apprenticeship.

Among those with some college experience or an associate degree, about seven-in-ten STEM workers (69%) say they have completed this kind of training, compared with about half of non-STEM workers (49%).

In addition, among workers with an associate degree, STEM workers are more likely than workers in other occupations to say their job is closely related to their education.

Some 77% of STEM workers with an associate degree say their job is closely related to their degree.

In contrast, about three-in-ten (28%) of those working in other occupations say their associate degree is closely related to their current job, while a larger share (42%) say their degree is not related or not very closely related to their job.

Similarly, STEM workers with an associate degree are about three times more likely than their non-STEM counterparts to say they use the skills and knowledge from their degree in their current job all the time (73% vs 24%).

Middle-skills jobs are particularly common in computer technology and healthcare. STEM middle-skills workers are distinct from middle-skills workers in other occupations because they are more likely to have additional educational training that is directly related to their job.

About three-in-ten science, technology, engineering, and math (STEM) workers (28%) have some college experience (including an associate degree) but no bachelor’s degree. This is a similar shape to those employed in non-STEM occupations (31%). Among those with some college experience, STEM workers earn 35% more than their non-STEM counterparts ($54,745 vs. $40,505).

In a recent American Worker series "Back to Work: Middle-Skill Jobs in the STEM Economy" RAND experts argue that raising awareness about high-demand occupations that need to be filled will further reconnect adults to the labor force.

"Without a clear signal of what opportunities are available, potential workers will not know where to direct their attention, what types of certificates and licenses to obtain, or where to pursue education and training," they said.

"With considerable attention and resources targeting the sub-baccalaureate labor market and middle-skilled STEM jobs, policy initiatives have the potential to reduce adult worker disconnection from the labor force and continue the forward momentum spurred on by the post-recession recovery."