Are international students fellowships always taxed in the US?

[1Q84]

I had a friend from the EU say after 4 years in the PhD, their fellowships stopped getting taxed. Canadian here and I've been taxed for 7 years now. I am gonna eventually talk to a tax accountant but just wondering if anyone here has anecdotes/experience/confirmation.

[Lewis-H]

According to Erwin, FDAP income includes “US-source dividends, certain interest, passive rents and royalties, non-qualified scholarships, compensation for services and other “fixed or determinable, annual or periodical income”. The flat rate on this is 30 percent on gross income.