W-2 Box 12 Codes

Lines a, b, c, and d of Box 12 on Form W-2 contain miscellaneous additional compensation and benefits, each identified with a letter code.

List of Box 12 Codes.

• A and B: Uncollected social security and Medicare tax on tips. This amount represents the social security and Medicare tax on the tips you reported to your employer. There will be an amount here if your employer didn't withhold social security or Medicare taxes on these tips. If you have one of these codes on your W-2, you cannot file a Form 1040EZ.
• C: Imputed Income for group-term life insurance, for informational purposes. This amount is also included in in Boxes 1, 3 and 5.
• D, E, F, G, S, and H: Amounts for contributions toward retirement accounts, for information only:
  • D: 401( k ) plan
  • E: 403( b ) plan
  • F: 408( k )( 6 ) plan
  • G: 457( b ) plan
  • S: 408( p ) salary reduction SIMPLE retirement account
  • H: 501( c )(18)( D ) plan
• J: Non-taxable sick pay.
• K: Excise tax for excess golden parachute payments.
• L: Amount employer reimbursed for employee business expenses using a per diem or milage allowance. For more information visit this IRS page on Employee Business Expense Reimbursements.
• M and N: Amount of social security and Medicare tax for imputed income (see C above) that was not withheld.
• P: Exclusionary moving expense reimbursements, not included in Box 1.
• Q: Nontaxable combat pay (applies to military employers).
• R: Employer contributions to an Archer MSA (medical savings account). Included in Box 1 of your W-2.
• T:Employer-provided adoption benefits.
• V: Income from exercise of non-statutory stock options, included in Box 1.
• W: Employer (and employee) contributions to an HSA. Also reported on Form 8889.
• Y: Deferrals under section 409( A ) on an nonqualified deferred compensation plan.
• Z: Income under section 409( A ) on a nonqualified deferred compensation plan. This amount is also included in Box 1. It is subject to an additional 20% tax plus interest.
• AA: Designated Roth contributions under a section 401( k ) plan.
• BB: Designated Roth contributions under a section 403( b ) plan.
• DD: Cost of employee deductions and employer sponsored contributions to health coverage, for informational purposes. Does not affect any other boxes. 
• EE: Designated Roth contributions under governmental section 457( b ) plan. This amount does not apply to contributions under a tax-exempt organization section 457( b ) plan.
• FF: Permitted benefits under a qualified small employer health reimbursement arrangement.

Please Note: Employer contributions to 401( k ) will not be reported in W-2 Box 12.

For more information on Box 12 codes visit this IRS page.