What Does Box 12 Code Z Mean on a W-2?
Income from a nonqualified plan that fails 409A. What it means, whether it is taxable, and what to do with it.
By the Easy Guides Editorial Team · Updated for 2026
Box 12 Code Z is income from a nonqualified plan that fails 409a.
What Code Z means
Income from a nonqualified deferred compensation plan that failed to meet section 409A requirements.
Does Code Z affect my taxes?
This is bad news on a form. The amount is included in box 1 and it carries an additional tax on top of ordinary income tax.
What to do about it
Report it as the Form 1040 instructions direct. A Code Z amount usually warrants professional advice, because the extra tax is significant.
Where to find Code Z on your W-2
Look at box 12, in the middle-right of the form. It has up to four lines, labelled 12a, 12b, 12c and 12d. Those letters are only line labels. The code you want is the small letter or pair of letters printed next to the amount, and it will read Z. If you have more than four entries, your employer issues a second W-2 to carry the rest.
Not the code you were looking for? The full box 12 code list covers every letter, and the W-2 box decoder explains every box on the form.