What Does Box 12 Code H Mean on a W-2?
501(c)(18)(D) contribution — what it means, whether it's taxable, and what to do with it.
By the Easy Guides Editorial Team · Updated for 2026
Code H in Box 12 of your W-2 means 501(c)(18)(d) contribution. Tax treatment: Pre-tax.
What Code H means
If it applies to you, it may allow a deduction — check the Form W-2 instructions, as the treatment is unusual.
Does Code H affect my taxes?
A contribution to a rare 501(c)(18)(D) tax-exempt pension trust. Almost nobody sees this code.
Where to find Code H on your W-2
Box 12 has up to four slots — labeled 12a, 12b, 12c, and 12d. Each slot shows a letter code and a dollar amount. The 12a–12d labels are just line numbers; the actual code is the small letter next to the money. So "12a: H 5,000" means Code H with a $5,000 amount. When you file, enter the code and amount exactly as shown.