I work in a State with no State tax (Tennessee). Box 15 of my W2 has "TN" in it. The dropdown window on Turbo tax does NOT have TN as a selection. How do I proceed?

You leave boxes 15, 16 and 17 entirely empty.  no numbers...no letters...empty

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Same thing for any other folks in a non-income-taxing state  (TX, FL etc)

That worked. thank you