Most professional MS programs will not offer financial support. Some programs may allow students to work as Teaching Assistants, but it may not cover the full tuition of the program. If you need financial assistance, you may want to check whether the university you are applying to offers financial support, including scholarships and loans, to MS students. These are often handled by a central office, and not by the MS programs themselves. Offices managing professional MS programs will have answers to such questions. Always ask, especially if you are deciding between multiple programs.
In most academic MS programs, students are eligible to work as TAs, which often covers the costs of tuition. It is not typical for an admitted student to receive financial support as part of their offer of admission, but support may become available over time. Always ask and complete forms to be placed on a TA waiting list. There may also be work opportunities in other departments or centers on campus.