Q. I travel for work in different state than I hold residency in? Do I need to file in both states?
A. Yes, but "nobody" does. See http://money.cnn.com/2013/06/28/pf/taxes/business-traveler-tax-threat/
If you work in the other state is more than just occasional, a regular thing, then yes, you you should file in both states.
But it may depend on what the two states are. Some states have reciprocal agreements on income tax. Reciprocity applies only to employees, not the self employed.
You may. So much depends upon the facts and the states that you are talking about. Each state defines full-year resident, part-year resident and nonresident differently. Some states have reciprocal agreements.
The nature of your income makes a difference, as well. Self-employment income might be easier to identify with one state or another. Employment income may or may not assign income and withhold income taxes on more than one state.
If you only lived in one state, that state will be your resident state. Other states may be nonresident states.
TurboTax asks simple questions and makes determinations within the software.
If you have questions, provide specific information and someone will assist you.
See also here.