Can I get a waiver of penalty if my Roth conversion was late in the year and couldn’t figure the tax in time?

[bteschel]

Roth conversion in December

[Bsch4477]

That wouldn’t qualify as an exemption. 

[NCperson]

@bteschel the payment was due by January 15,  

You can use  form 2210 to reduce the penalty.

https://www.irs.gov/pub/irs-pdf/f2210.pdf

Here's why: Unless you use that form, the IRS assumes your income was the same each month of the year and the tax was due quarterly based on that smooth income.  However, your income was probably "lumpy" since you completed a Roth conversion late in the year.   Form 2210 will adjust for that.  It won't eliminate the penalty but it will reflect that the penalty should only be for the 4th quarter.