If you are only in Pennsylvania to attend school, you are considered a New York resident for tax purposes. To file your return this year, you will file a non-resident Pennsylvania return to report the Pennsylvania income only. You will also need to file a New York resident return to report all income, including the PA income. New York will provide a credit or allowance for the tax already paid to Pennsylvania. (You will not be taxed twice on the same income.)
In the Personal Info section of Turbo Tax, you will select NY as the state you were a resident of on 12/31/15. Indicate you did NOT live in another state, as time spent away at school is treated as if you were in your resident state. When you get to the question asking if you earned income in another state, respond Yes and enter PA as that state.
Thanks for the info. When completing the Free on line filing, should we be asking to do the PA first and then NYS? Most programs only allow for 1 free State filing.
Prepare the nonresident PA tax return first. See here.
The resident NY tax return will provide you a credit for the tax you paid to the nonresident PA tax return.
There may be an additional charge for a second state tax return.