You must file a non-resident DE tax return in addition to your home state PA return. You'll be able to claim a credit amount on your PA return for the taxes paid to DE on the income that is taxed by both states. But you must prepare the non-resident DE return first, before you do your PA return, in order for TurboTax to calculate and apply the credit correctly.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
