A Roth 401(k) match comes in two versions. Choosing Roth for your own 401(k) contributions does not by itself decide how your employer’s match is treated. SECURE 2.0 let employers offer Roth treatment for matching contributions, so there are now two versions of a match: the traditional pre-tax version and the optional Roth version. The Roth version has a tax effect in the year of the contribution, which surprises people who expect no bill. Here is what the sources say, an example with assumed numbers, and steps that make the Roth version a manageable choice.
Two Versions of the Match
Before December 2022, employer matching contributions could go only into pre-tax accounts (AOL Finance). SECURE 2.0 Section 604, effective December 29, 2022, allows matching and nonelective contributions to be designated as Roth. IRS Notice 2024-2, released December 20, 2023, provides initial guidance, though a law-firm summary notes it is not comprehensive and further guidance is expected (Caplin & Drysdale).
What the Sources Say About the Roth Version
- Optional. A plan may allow Roth designation for all, some or none of salary deferrals, matching contributions and nonelective contributions. If offered, employees must be able to change their designation at least once per plan year (Caplin & Drysdale).
- Vesting. Designation is available only for a contribution type in which the employee is fully vested when the contribution is allocated (Caplin & Drysdale).
- Taxable when added. The amount is includible in gross income for the year it is allocated to the account (Caplin & Drysdale).
- No withholding. It isn’t treated as wages for income tax withholding, so employees may need to adjust withholding or make estimated payments to avoid underpayment penalties. It is also not treated as wages for Social Security, Medicare or FUTA, with an exception for certain governmental plans on the FICA side (Caplin & Drysdale).
- Reporting. It is reported on Form 1099-R for the year of allocation.
- Timing. Tax follows the calendar year the contribution is allocated, not the plan year it relates to, and employers can deposit prior-year contributions up to the tax filing deadline, including extensions (AOL Finance).
- Election timing. AOL Finance says the election must be made before allocation and becomes irrevocable once the deposit is made (AOL Finance).
Roth 401k Match Tax Surprise: An Example With Assumed Numbers
Assume a $4,500 Roth match. The added federal income tax depends on your marginal bracket, which I assume here. The tax is the match times the rate, with nothing withheld on that amount.
| Assumed marginal rate | Added federal tax |
|---|---|
| 12% | $540 |
| 22% | $990 |
| 24% | $1,080 |
AOL Finance gives a similar illustration: a $5,000 Roth match at a 22% marginal federal rate creates $1,100 in additional federal tax with no withholding (AOL Finance). The actual tax depends on your whole return.
Tax Filing Points
AOL Finance notes a preparer may not recognize the 1099-R because it shows a distribution you never took. It cites Morningstar’s Denise Appleby as recommending giving your preparer a copy with a written explanation and contacting the plan administrator if the form has errors, and it warns that misreporting the amount as an early distribution could trigger a 10% early withdrawal penalty (AOL Finance). A law-firm summary adds that this reporting may significantly increase annual paperwork, since 1099-Rs are not usually issued to active participants (Caplin & Drysdale).
Roth 401(k) Match: Turn the Tax Into a Small Per-Paycheck Number
The easiest way to remove the surprise from a Roth 401(k) match is to split the expected tax across the year. The IRS says people who receive wages can avoid estimated tax payments by asking their employer to withhold more, using a new Form W-4 that has a special line for an additional amount to be withheld. It also says payments can be made weekly, biweekly or monthly as long as enough has been paid by the end of each quarter, and that individuals generally must pay estimated tax if they expect to owe $1,000 or more when they file (IRS: Estimated taxes).
Using the $4,500 match at an assumed 22% rate, the added tax is $4,500 × 0.22 = $990. Spread across 26 biweekly paychecks, that is $990 ÷ 26 = $38.08 per paycheck. Spread across 12 monthly payments it is $990 ÷ 12 = $82.50. If you start in mid-year with 13 biweekly paychecks left, it is $990 ÷ 13 = $76.15. For comparison, the IRS says most taxpayers avoid the underpayment penalty if they owe less than $1,000 after filing, or if they pre-pay at least 90% of the current year’s tax or 100% of the prior year’s, whichever is less, with 110% of the prior year for AGI above $150,000 (IRS CP30B notice page). Because the added $990 is nearly the $1,000 line by itself, adding it on top of any other balance due can cross the line, which is a good reason to set the extra withholding early.
A simple routine for a Roth 401(k) match: when the plan tells you the match will be Roth, compute the match times your marginal rate, divide by the number of pay periods left, and enter that figure on the W-4 extra-withholding line. The marginal rate and match amount in these calculations are assumed, so substitute yours.
A Plan For Handling It
- Confirm your plan offers it. Employers aren’t required to, and recordkeepers aren’t required to support expanded Roth programs (Caplin & Drysdale).
- Check your vesting. Roth designation applies only to contribution types in which you are fully vested.
- Model the tax before electing. Multiply the expected match by your marginal rate, as in the table above.
- Set aside cash for the bill, or adjust W-4 withholding or estimated payments. The sources say employees may need to do one of these.
- Look for the 1099-R in the following tax season, and share it with your preparer with a note.
- Review the choice each year, since employees must be able to change the designation at least once per plan year.
Who Might Prefer Which Version
AOL Finance says younger workers in lower brackets, with more years of tax-free compounding, may benefit most from the Roth version, while higher earners nearing retirement should weigh whether the upfront tax outweighs future tax-free withdrawals (AOL Finance). That is that article’s view. In my view, the answer depends on your current bracket and your cash flow for paying the tax.
My Take on Roth 401k Match Tax Surprise
- In my view, a Roth match is worth modeling before electing, since the tax arrives in the year of deposit with no withholding.
- In my view, setting money aside during the year, or adjusting W-4 withholding or estimated payments, is a straightforward way to cover that bill.
Sources
- Caplin & Drysdale: IRS guidance on Roth option for employer contributions
- AOL Finance: Roth 401(k) match could trigger a surprise tax bill
- IRS: Notice 2024-2
- IRS: Estimated taxes
- IRS: Understanding your CP30B notice
Related reading: Super Catch-Up Roth Mandate — What Changed for High Earners and Take-Home Pay After a Raise: The Exact Math.
This article offers general information and my own opinions, not financial, tax, or legal advice. The figures in worked examples are assumed. Laws, tax rules, and products change and can differ by location, so check current official sources and talk to a qualified professional about your own situation.