Get your taxes done using TurboTax

You won’t get your official 1099-R until early 2027, but you’ll need to report this income on your 2025 return now. Here are the exact steps for reporting each piece on your 2025 return:

Step 1: Report the Traditional 401(k) Excess

Because this amount was "pre-tax," it was excluded from your W-2 Box 1. You must now include it as wages.

1. Look for the "Wages & Income" section. Instead of just adding it to your W-2, look for "Less Common Income" -> "Miscellaneous Income" -> "Other income not already reported on a Form W-2 or Form 1099."
2. When prompted for a description, enter "2025 Excess 401(k) Deferral."
3. The Amount: Enter only the principal excess contribution amount.
4. Result: This ensures the amount lands on Form 1040, Line 1h, which tells the IRS, "I had extra wages that weren't on my W-2."

Step 2: Report the Roth 401(k) Earnings

Since the Roth contribution itself was already taxed (it’s already in your W-2 Box 1), you do not report the principal. You only report the taxable interest/earnings generated by that excess.

1. Where to enter: Use the exact same "Miscellaneous Income / Other income not reported on a W-2" path used in Step 1.
2. The Description: Enter "2025 Excess Roth 401(k) Earnings."
3. The Amount: Enter only the earnings/interest portion.
4. Note: Per IRS rules, for a timely correction, Roth earnings are taxable in the year the contribution was made (2025).

Step 3: Dealing with Traditional 401(k) Earnings (The "Wait" Part)

1. Don't report these now: Unlike Roth earnings, earnings on a Traditional 401(k) excess are generally taxable in the year they are distributed (2026).
2. Action: You will report these on your 2026 tax return (filed in 2027) once you receive the actual 1099-R.