Recent policies across the United States support rigorous high school computer science courses acting as flex credit courses. This allows the courses to count as graduation requirements in lieu of traditional mathematics or science courses. In this study, 457 teachers in high schools that had not yet adopted flex credit policies indicated school readiness and personal beliefs regarding counting computer science as a mathematics or science requirement. Tangible first-order barriers (e.g., appropriate curriculum) were greater hurdles than intrinsic second-order barriers (e.g., beliefs). Other notable findings included viewing computer science counting as a mathematics requirement more favorably than as a science requirement; science teachers being least positive about computer science as a core requirement; and school socioeconomic status and enrollment size not being correlated to perceptions.