This paper examines teacher earnings to provide empirical evidence on the sources and the extent of gender gaps in the teaching profession. Using data from two waves of the National Teacher and Principal Survey, we show that on average male teachers have a small advantage of over $700 in base pay (1.3 % of the sample average) compared to female teachers with similar characteristics and in similar contexts. Men also significantly outearn women, all else equal, on three of four different types of school-based supplemental compensation, raising the adjusted earnings gap to 7.2 % of total school earnings. Teachers’ participation in extra duties and the likelihood of earning compensation for them differ by gender. Male teachers are both more likely to perform extra duties and receive compensation for those activities than female teachers, and the earnings gap increases when schools have a male principal. Our results provide insight into teacher compensation and have implications on practices that could promote more equitable pay.