Is it possible that your withholding this year meets or exceeds your 2017 tax liability?
In general, you may owe the penalty for 2018 if the total of your withholding and timely estimated tax payments didn't equal at least the smaller of:
1. 90% of your 2018 tax, or
2. 100% of your 2017 tax. Your 2017 tax return must cover a 12-month period.
There are also exceptions to the penalty:
You won't have to pay the penalty or file this form if either of the following applies.
• You had no tax liability for 2017, you were a U.S. citizen or resident alien for the entire year (or an estate of a domestic decedent or a domestic trust), and your 2017 tax return was (or would have been had you been required to file) for a full 12 months.
• The total tax shown on your 2018 return minus the amount of tax you paid through withholding is less than $1,000
https://www.irs.gov/pub/irs-pdf/i2210.pdf
