They aren't. Most or at least some of tuition is waived. Students get a stipend, since you are often prohibited from taking employment. If they take employment,

They aren't. Most or at least some of tuition is waived. Students get a stipend, since you are often prohibited from taking employment. If they take employment, it is often paid by grant, and related to research in the field of study. Some get TA work. As I said in another comment ITT, American students won't work for the meager stipends that most schools can offer.