Research PhD Programs and PSLF (Public Service Loan Forgiveness)

I called Federal Student Aid, but the answer I got was a little unclear. If you're pursuing a research PhD and receiving a stipend from a grant for the program, does that count towards 10 years of employment for a non-profit under PSLF? Not sure if it makes a difference, but in my case, this would be for a research PhD in Earth or planetary sciences.