Thanks! Maybe that's what he meant. For one semester this fall my tuition is more than 12K and next semester tuition is expected to be even more. I'm guessing the COE is handled through the actual department and the NSF CO really has little control over it.
Do you know if tuition is paid for during summer semesters? The GRFP handbook seems pretty vague on that. My assumption is you still get a stipend for the summer but have to pay tuition even if you're just signed up for research credits?