It's a deduction, so it only reduces your taxable income; not the actual tax.

So you are saying my paycheck will not change no matter what is written on 4b?

My taxable gross is the exact same for December 2022 and January 2023. Does that mean my updated W-4 has not been processed?

No. I mean that your taxable income is reduced by $6000. The withholding would only reduce by the amount of taxes you no longer have to pay on that $6000. Depending on how much you are making it seems like they reduced your withholding by $50 which lines up if you are making less than $20k a year.

A deduction reduces your taxable income, which indirectly reduces your tax by whatever your marginal tax rate happens to be.

For example, in the 12% tax bracket, a $4800 deduction reduces your tax by 0.12 x 4800 = $576 over the course of the year, or $48 per paycheck if you are paid monthly.

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Thank you! This answered my question

Oh then the numbers check out. $4800 * .12 / 12 is about $48 less in tax a month.

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You gotta factor in the standard deduction. Your rate is basically at 12%

Thank you so much!