Yes. Interest is taxable, even if it is below the reporting threshold for a 1099-INT. In order to report this, you can enter the information into TurboTax the same way you would have if you had received a 1099-INT.
Here's how to enter a 1099-INT into TurboTax Online:
- Under "Let's import", choose "Enter a different way."
- Choose Interest, continue
- Choose "Type it in myself"
- Enter the information regarding the interest you received.