Did you get a 1099 INT for it?
Enter a 1099-Int under
Federal
Wages & Income
Interest and Dividends
Interest on 1099-INT - Click the Start or Update button
If you didn't get a 1099 put the total in Box 1.
You should have received a form 1099-INT.
In TurboTax Online, you can enter your form 1099-INT by following these steps: