Tax the Students (Picture)

I'm a dual citizen with the U.S. and New Zealand, but I've lived in NZ since I was a child. The scholarship I received covers all course-related costs and comes with a $28k (NZD)/annum living stipend (approx $17k USD) to cover basic living necessities. The stipend is based on the fact that it is non-taxable in NZ and is my primary source of income. I always have to file taxes in the U.S. but I usually don't owe anything because the NZ tax rate is higher (it's all very complicated and a nightmare every year). I've never worked in the U.S. and haven't lived there for almost 15 years. If anyone is an expert on U.S. taxes and can tell me if I've missed something I'd be grateful.