Originally posted by Primate
You do pay state [of PA tax].
http://www.revenue.state.pa.us/revenue/cwp/view.asp?A=238&QUESTION_ID=171167
"(3)_ Fellowship awards or fellowship stipends made to a graduate student enrolled in a graduate degree program at a university chartered by a state or foreign country on the basis of need or academic achievement for the purpose of encouraging or allowing a recipient to further his educational development are not taxable._ When the fellowship awards or fellowship stipends are made as compensation for past or present employment or in expectation of future employment services they are taxable."
"(4)_ Fellowship awards and fellowship stipends are taxable compensation for services if the recipient is required to apply his skill and training to advance research, creative work or some other project or activity,
unless the recipient can show that he is a candidate for a degree and the same activities are required of all candidates for that degree as a condition to receive that degree."
The conclusion on that page:
"The $10,292 research assistantship_received [for a M.S. or Ph.D.] in exchange for research will not be taxable for Pennsylvania personal income tax purposes, pursuant to the above regulations, so long as the research she conducts is required of all degree candidates."
This is further echoed here:
http://www.revenue.state.pa.us/revenue/lib/revenue/rev-614.pdf
Q. What is the criteria for excluding a fellowship award or stipend from taxable compensation?
...,
or
(c) The recipient is a candidate for a degree, and the same activities are required for all candidates for that degree as a condition to receiving such a degree.
There's a few other places on the department of revenue site that say similar things. This all leads me to believe that we don't owe PA state tax.
Oh, and about external funding increases to stipends. The policies on that vary widely from school to school, just like the policies on loans. At some schools, you get nothing if you get external funding, the program takes it all. At other schools, you get some "Travel funding" or "computer funding", but no increase to your salary. At other schools, you get a fixed salary increase no matter how much stipend you get. Then at other schools, you qualify for an increase depending on how much money you get in external funding (up to a certain cap, varies).