Code A: Uncollected Social Security or RRTA Tax on tips.
Code B: Uncollected Medicare Tax on tips.
Code C: Taxable Cost of Group-Term Life Insurance over $50,000.
Code D: Elective Deferrals under Section 401(k) Cash or Deferred Arrangement Plan.
Code E: Elective Deferrals under a Section 403(b) Salary Reduction Agreement.
Code F: Elective Deferrals under a Section 408(k)(6) Salary Deduction.
Code G: Elective Deferrals and Employer Contributions to any Governmental or Nongovernmental Section 457(b) Deferred Compensation Plan.
Code H: Elective Deferrals under Section 501(c) (18) (d) Tax-Exempt Organization Plan.
Code J: Nontaxable Sick Pay
Code K: 20% Excise Tax on Excess Golden Parachute Payments.
Code L: Substantiated Employee Business Expense Reimbursements.
Code M: Uncollected Social Security or RRTA Tax on Taxable Cost of Group-Term Life Insurance over $50,000 (for former employees).
Code N: Uncollected Medicare Tax on Taxable Cost of Group-Term Life Insurance over $50,000 (for former employees).
Code P: Excludable Moving Expense Reimbursements Paid Directly to Employee.
Code Q: Nontaxable Combat Pay.
Code R: Employer Contributions to an Archer MSA.
Code S: Employer Salary Reduction Contributions under a Section 408(p) Simple Plan.
Code T: Adoption Benefits.
Code V: Income from the Exercise of Nonstatutory Stock Options.
Code W: Employer Contributions to a Health Savings Account (HSA).
Code Y: Deferrals under a Section 409A Nonqualified Deferred Compensation Plan.
Code Z: Income under Section 409A Nonqualified Deferred Compensation Plan.
Code AA: Designated Roth Contributions under a section 401(k) Plan.
Code BB: Designated Roth Contributions under a Section 403(b) Plan.
Code DD: Cost of Employer-Sponsored Health Coverage.
Code EE: Designated Roth Contributions under a Government Section 457(b) Plan.