You used the term interest "earned", but was the interest credited and paid in 2018? Your bank should have given you a 1099-INT if they actually paid interest into the CDs in 2018. It might be considered paid even though you choose to have it accumulate with the CD and didn't withdraw the credited interest. If you didn't receive a 1099-INT, you may have to ask your bank if it's not clear whether you actually received "credited and paid interest" or not.
