I would first print your 2016 and 2017 returns and compare them
line by line. This will help you determine what has changed, if there are any
discrepancies/items you missed or if you need to change any of the information
you entered into TurboTax.
There are several factors that go in to determining the
taxes you owe.
If your income increased, which might have put you in a
higher tax bracket, it could have reduced or eliminated some deductions or
credits and the tax laws changing year to year will determine the amount of
taxes that need to be paid as well.
If your income decreased, that sometimes can reduce your refund
due to you not having enough earned income to receive the deductions or credits
you did before.
