This year I am getting a penalty for underpayment of estimated taxes. I don't understand - I have never paid estimated taxes and never had a penalty like this before?

[BillM223]

We in the Community cannot see your tax return nor the screen you are on.

Generally, you receive a penalty for the underpayment of estimated tax if (1) your withholding and estimate tax payments (if any) were less than what your taxes assessed were last year, (2) you did not have sufficient withholding and estimate taxes paid in 2019 to cover your taxes assessed, and (3) you net tax due is $1,000 or more.

What was different between your return this year and last year?

[Stinkerbellkity]

You need to go through the interview for Underpayment Penalty under Other Tax topics.   Your entries there can result in no penalty owed

[VictorW9]

It is possible for you to have a refund AND have an underpayment penalty assessed.