On my 2019 return, I mistakenly entered on box 12 a B (instead of a D) which resulted with assessed with huge additional tax on my 1040/Line 24 -Total Additional Medicare TaxWithholding.
I have no idea how to correct this, I can't figure out how to explain typographical entry on my W2 (my fault) within in the context of the 1040x amended return. Could you let me know how to to this if you would?
