How to adjust to change in federal supplemental tax rate?

[notataxguru1999]

The tax act of 2017 decreased the federal supplemental tax rate from 25% to 22% which means less is tax is being collected by my employer for stock grants and I may be underpaying.  Since I don't know how much stock I'll receive from my employer in advance, how should I adjust to reduce how much I owe in April 2019?  Are others guessing how much stock they'll get and adjusting their W-4?

Federal supplemental tax rate: https://www.patriotsoftware.com/payroll/training/blog/wp-content/uploads/2018/01/income-tax-withhold...

[Carl]

There's really no need to adjust the W-4 if you don't want to. You may find it easier and simpler to pay any tax you think may be due in addition to your withholding, at http:www.irs.gov/payments. Make sure you print out your receipt and file it with your 2018 tax paperwork so you'll have it and remember to enter it at tax filing time.