Based on data from a 2012 Census Bureau study, about 48% of college graduates between 25 and 34 years of age with degrees in science, technology, engineering or math-related fields were working in a related field. STEM occupations include computer scientists and mathematicians; engineers and architects; life, physical, and social scientists; medical professionals; and managers of STEM activities.
When adjusted to include workers up to age 64, this percentage dropped to about 25%, suggesting a large portion of STEM workers end up changing their field at some point later in their careers.