@MythSaraLee
The issue you might have, is that the payroll people may not be able to implement your changes this late in your pay cycle. Normally, the change you make might only be applied to the next wage cycle.....which might not exist for you.
If it doesn't happen, you could just increase your withholding on your pension payments, to make up for what wasn't withheld in your working paychecks.
Use the W-4P to increase withholding from a pension
About Form W-4P, Withholding Certificate for Periodic Pension or Annuity Payments | Internal Revenue...
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
