PhD students in the Chemistry, Biology, and Biochemistry programs are guaranteed to have funding for at least five years in the form of Research Assistantship (RA), Teaching Assistantship (we call it AI-ship here, AI for Associate Instructor), or Fellowship. All applicants are automatically entered for any eligible University/Departmental fellowships during the application process. What all these mean is that if you get an offer from these programs at IU, you receive tuition remission, health insurance, and a good stipend for at least five years.
For Master’s students, teaching positions are always available too as we have lots of undergraduate level classes that need AI’s majoring in these fields.
Now if you are brining your own external funds, that would be even better because you wouldn’t worry about having to teach at some point during your graduate career and would be able to focus full-time on your research. One to two semesters of teaching experience, however, is part of the requirements for your degree.