Garmaine Staff asked 5 months ago

I (US citizen working in the US) just received my paycheck and saw that my anticipated takehome pay was cut by 70% by a line item deduction titled "PYA Tax Adjustment". I have never seen this on any previous paychecks in my life and have no clue what it is; I would have contacted payroll but the office was closed on Friday due to holiday. I have read here that it refers to "prior year unallowed losses that are now deductible." I don't even understand what that means. My only guess is that it has to do with income that I incorrectly did not withhold the previous year, but I expected to simply pay this when filing my taxes? Why would it be deducted by my employer?