Railroad W-2 Box 14 Codes: Tier 1, Tier 2, and Excess Refunds

The codes crowded into Box 14 of a railroad W-2 are Railroad Retirement Tax Act (RRTA) items: your total RRTA compensation, the Tier 1 retirement tax withheld, the Tier 2 supplemental tax, the Medicare portion, and — once your pay crosses $200,000 — the Additional Medicare Tax. They sit in Box 14 because railroad employers leave the usual Social Security and Medicare boxes (3 through 6) blank. Reading the railroad W-2 Box 14 codes correctly is what lets your return calculate the right tax and, if more than one employer withheld from you, recover any excess.¹

Why the Usual Boxes Are Empty

RRTA replaces FICA for railroad employees. Because you don’t pay into Social Security through your railroad job, your employer leaves Boxes 3, 4, 5, and 6 blank and reports the equivalent retirement and Medicare figures in Box 14 instead. Blank Social Security boxes on a railroad W-2 are correct, not a payroll error. Tax software and preparers who don’t work with railroad forms often flag this as a problem; it isn’t.

RRTA itself is a two-tier system. Tier 1 mirrors FICA: 6.2% for retirement plus 1.45% for Medicare, matched by the employer. Tier 2 is a supplemental pension layer with no FICA equivalent — 4.9% from the employee in 2026, with the employer paying 13.1%.²³⁴

What Each Box 14 Abbreviation Means

The IRS tells railroad employers to label each Box 14 line but doesn’t dictate the abbreviations, so different carriers use different shorthand for the same item.⁵ The labels below cover the ones you’re most likely to see.

RRTA Comp, RR Comp, or Tier 1 Comp. Your total compensation subject to RRTA. This is a wage figure, not a tax amount, and it generally tracks Box 1. Your software uses it to check whether your Tier 1 withholding fits the wage base.

T1, Tier 1 Tax, T1T, or RRTA-T1. The 6.2% Tier 1 retirement tax actually withheld from your paychecks. This is the railroad counterpart to the Social Security tax that would normally sit in Box 4.

T2, Tier 2 Tax, T2T, or RRTA-T2. The 4.9% Tier 2 supplemental pension tax withheld. No FICA line corresponds to this.

Med, Medicare, or RRTA Med. The 1.45% Medicare tax withheld on your RRTA compensation. Functionally the same as FICA Medicare.

Add Med Tax, Addl Medicare, or RRTA Add Med. The 0.9% Additional Medicare Tax withheld on RRTA compensation above $200,000 in the calendar year.⁶

T1W or RRTA1. Wages subject to Tier 1 tax — the wage figure the tax is computed on, not the tax itself. Some employers list this separately from total RRTA compensation.

T2W or RRTA2. Wages subject to Tier 2 tax. Because the Tier 2 wage cap ($137,100) is lower than Tier 1’s ($184,500), this figure will be smaller than your Tier 1 wages if you earned above the Tier 2 cap.

GTL or Group Term Life. The taxable cost of employer-provided group term life insurance above $50,000 of coverage. Railroad employers report this in Box 14a in addition to Box 12 Code C.⁵

If an abbreviation on your W-2 doesn’t match any of these, call your employer’s payroll office before you file. Guessing at a code can push a Tier 1 amount into a Tier 2 slot and either kill an excess-withholding credit you’re owed or generate a false alert about over-withholding.

Entering the Codes in Tax Software

TurboTax, H&R Block, and FreeTaxUSA all handle railroad W-2s, but none of them auto-recognize the abbreviations. You have to map each Box 14 line to a category by hand.

For every code-and-amount pair, type the label your employer used, enter the dollar amount, then pick the matching category from the dropdown. The categories are usually named “Railroad Retirement Tier 1 Tax,” “Railroad Retirement Tier 2 Tax,” “Railroad Retirement Medicare,” and “Railroad Retirement Compensation,” and they tend to sit near the bottom of a long alphabetical list.

Two mistakes to avoid. Don’t drop your Tier 1 tax into Box 4 (Social Security tax withheld) — Box 4 should be blank in your software entry, exactly as it is on the paper W-2. The software needs Tier 1 to arrive through Box 14 to compute the excess-withholding credit properly. And enter your total RRTA compensation as its own Box 14 line, categorized as railroad retirement compensation; some programs use that figure to decide whether you have an overpayment, and skipping it can trigger a phantom warning that your employer over-withheld.

Recovering Excess Withholding

If you worked for more than one employer in 2026 — two railroads, or a railroad plus a non-railroad job — each one withheld as if it were your only job. Combined withholding can easily blow past the annual maximum, and the recovery method depends on which tier ran over.

Excess Tier 1 Tax

The maximum Tier 1 retirement tax per employee in 2026 is $11,439 (6.2% of $184,500). Anything withheld above that from multiple employers is claimed as a refundable credit on Schedule 3, Line 11 of Form 1040. The credit either cuts what you owe or adds to your refund.⁷ Add up the Tier 1 retirement tax from every W-2, subtract $11,439, and the difference is your credit. Tax software calculates this on its own if you categorized Box 14 correctly.

The credit only applies when the over-withholding came from more than one employer. If a single employer withheld too much Tier 1 on its own, you can’t take the credit on your return — you have to ask the employer to correct it.⁸

Excess Tier 2 Tax

Tier 2 works differently, and this is where people lose money. You cannot claim excess Tier 2 on Form 1040 or Schedule 3, even when multiple railroad employers caused the overpayment. You file Form 843, Claim for Refund and Request for Abatement, directly with the IRS.⁸

The 2026 Tier 2 maximum is $6,717.90 (4.9% of $137,100). If combined Tier 2 withholding from multiple railroad employers exceeds that, complete Form 843, check box “a” for employment tax on Line 4, write “Excess tier 2 RRTA” on Line 8, show your computation, and attach copies of every W-2 for the year.⁹

Single-Employer Over-Withholding

If one employer took too much of either tier, you have to go to the employer first. Only if the employer refuses or fails to correct it do you file Form 843. Attach a statement from the employer indicating whether any portion was already reimbursed; if you can’t get one, include your own written explanation along with copies of your W-2s.⁹

Deadline

You generally have three years from the date you filed your original return, or two years from the date you paid the tax, whichever is later, to submit Form 843. After that, the refund is gone.⁹

The Additional Medicare Tax Line

The 0.9% Additional Medicare Tax applies once your compensation crosses a filing-status threshold:¹⁰

Single or head of household: $200,000
Married filing jointly: $250,000
Married filing separately: $125,000

Your employer starts withholding the additional 0.9% once your RRTA pay hits $200,000 in the calendar year, regardless of your actual filing status. If you’re married filing jointly, your real threshold is $250,000, so you’ll reconcile any over-withholding on your return.⁶

A wrinkle unique to railroad workers: RRTA compensation is measured against the threshold separately from other wages or self-employment income. If you had both railroad and non-railroad income the same year, each is evaluated on its own before they meet up on your return.

Sick Pay and Disability Entries

You may also see a Box 14 line tied to sickness or disability benefits paid under the Railroad Unemployment Insurance Act. These benefits are excluded from Tier 1 taxes to the extent they qualify as sickness benefits, and the Box 14 entry usually shows the amount that was excluded from RRTA withholding rather than a tax amount.¹¹ Check this figure when you’re reconciling your totals; it affects how much of your compensation is taxable.

1
Railroad Retirement Board. Chapter 05 Form W-2, Wage and Tax Statement and Form W-3, Transmittal of Wage and Tax Statements
2
Railroad Retirement Board. Notice of Annual Rates 2026
3
Railroad Retirement Board. Railroad Retirement and Unemployment Insurance Taxes in 2026
4
Social Security Administration. Contribution and Benefit Base
5
Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
6
Internal Revenue Service. Questions and Answers for the Additional Medicare Tax
7
Internal Revenue Service. 2025 Schedule 3 (Form 1040) – Additional Credits and Payments
8
Internal Revenue Service. Topic No. 608, Excess Social Security and RRTA Tax Withheld
9
Internal Revenue Service. Instructions for Form 843 (12/2024)
10
Internal Revenue Service. Topic No. 560, Additional Medicare Tax
11
Internal Revenue Service. Railroad Retirement Tax Act (RRTA) Desk Guide (January 2009)