To establish a common understanding of terms used to describe the STEM labor force in this report, the following definitions will be adopted throughout the report.

STEM occupations are a subset of all U.S. occupations that utilize science, engineering, mathematics and/or technology in the primary functions of their job. Workers in STEM occupations can have any educational background. For example, while the majority of STEM middle-skill occupations were comprised of those without a bachelor’s degree in 2021, about 12.7% (1.8 million) had a bachelor’s degree or higher (Table SLBR-1). Similarly, 22.3% of S&E workers (2.1 million) and 37.5% of S&E-related workers (5.1 million) did not have a bachelor’s degree.

For the purposes of this report, STEM occupations can be broken into three distinct groups:

1. Science and engineering occupations (i.e., S&E occupations)
2. Science and engineering–related occupations (i.e., S&E-related occupations)
3. STEM middle-skill occupations

STEM middle-skill occupations were first identified in the previous Indicators 2022 labor report to more fully describe the modern-day STEM economy. They represent occupations not previously identified as S&E or S&E-related that have incorporated technical knowledge into core work. STEM middle-skill occupations are performed by individuals with more diverse educational backgrounds than described by the traditional definition of S&E occupations (NSB 2021).

STEM occupations or STEM groups will be used to collectively refer to the three groups of occupations listed above (i.e., S&E, S&E-related, and STEM middle-skill occupation groups). A description of S&E occupations, S&E-related occupations, and STEM middle-skill occupations can be found in the Diversity and STEM: Women, Minorities, and Persons with Disabilities 2023 sidebar The STEM Workforce of the United States. See Table SLBR-1 for a list of occupations found in the 2021 ACS 1-year Public Use Microdata Sample (PUMS) and their classification into these STEM groups.

The STEM workforce is comprised of workers in S&E, S&E-related, or STEM middle-skill occupations, regardless of their educational attainment or field of degree. The skilled technical workforce (STW or STW workers) is a subset of the STEM workforce and represents workers without a bachelor’s degree who are employed in any of the identified STEM occupations (i.e., S&E, S&E-related, or STEM middle-skill occupations).