RSU stock price change as a reason for underpayment penalty waiver

[kkurni]

Can I use "RSU stock price/inflation change" as a reason for underpayment penalty waiver?

I have used W4 estimator to calculate my federal tax withhold and add some buffer.
However, due to RSU stock price increase when vested, it does not calculate the tax withhold well.

Can I use that to apply as underpayment penalty waiver?

[Mike9241]

you can use PART II item B of 2210 to request a waiver. you'll not be able to e-file because you must include an explanation of why you think you are entitled to a waiver.

If you checked box B, complete Form 2210 through line 18 without regard to the waiver. Enter the amount you want waived in parentheses on the dotted line next to line 19. Subtract this amount from the total penalty you figured without regard to the waiver, and enter the result on line 19 .
Attach Form 2210 and a statement to your return explaining the reasons you were unable to meet the estimated tax requirements and the time period for which you are requesting a waiver.

The IRS will review the information you provide and decide whether to grant your request for a waiver.