Dual enrollment opportunities have grown dramatically across the United States since the beginning of the 21st century as increasing numbers of high school teachers are credentialed to provide college courses to their students. Dual enrollment has grown from a small advancement opportunity for students who had finished high school requirements before the end of high school into a strategy to introduce college course taking to students who might not otherwise experience postsecondary education.

A growing body of evidence that dual enrollment can significantly improve students’ educational achievement and attainment has helped sustain and accelerate this expansion. Between 2002 and 2010, the number of high school students taking dual enrollment courses doubled to roughly two million; by 2016, 47 of 50 states (and the District of Columbia) had adopted a statewide dual enrollment policy.

Dual enrollment is particularly effective when high schools prepare students for a sequence of college credit courses so that students enter postsecondary with a year or more of credit already completed in a career area or major of interest.

In some quarters—especially among stakeholders in higher education—this rapid expansion has generated concern about quality. Are credentialed high school teachers providing coursework that is equivalent to that taught on the college campus by a professor? In Texas, where the growth of dual enrollment has been especially explosive, the state’s commissioner of higher education noted in 2016, “I get concerned when I see that huge numbers of students are taking dual-credit courses and those numbers aren’t consistent with the data that we have on college readiness.” Policy makers and educators in other states have echoed this concern.

This piece provides a state-by-state policy analysis for Illinois, Ohio, and Wisconsin to explore key themes related to offering dual enrollment effectively and at scale: teacher credentialing standards, systems for monitoring quality of the courses taught, and how to fund growing demand.