I overpaid 2016 state taxes. i did not receive a refund. Received letter wit instructions to claim on 2017 tax return. Where to enter on 2017 return?

To apply last year's state refund to the current year's state tax payments in TurboTax: 

• Select Federal>Deductions & Credits>Estimates and Other Taxes Paid>Other Income Taxes>Start or Revisit>click "Yes" on the "About other income taxes" screen
• Add your prior year state and local income tax refunds to "2016 Refund Applied to 2017" and continue through the interview.