During the 2012-13 school year, approximately 27,000 teachers taught at least one physics course in a U.S. high school. About one-third of those teachers have earned a degree in physics or physics education; the vast majority of the others have earned degrees in a variety of other science fields. About 53,000 physics classes were taught, ranging from conceptual physics through AP and second-year physics classes. Using data from our 2012-13 Nationwide Survey of High School Physics Teachers, we look at the teaching experience and academic preparation of teachers teaching various physics classes. We see that teachers with a degree in physics or physics education teach mostly physics classes (as opposed to non-physics). Furthermore, teachers with physics teaching experience and a degree in physics or physics education teach more AP and Honors physics classes than any other group of teachers.