Rolling money out of a 401(k) sounds simple until the check arrives — and it is 20% smaller than the balance the participant expected. That gap is not a mistake. It is the mandatory federal withholding that applies whenever a distribution from an employer retirement plan passes through the participant's hands before landing in a new retirement account. For workers changing jobs or consolidating accounts in 2026, understanding this rule is the difference between a clean tax-free rollover and an unplanned tax bill with a 10% penalty attached.
Why the 20% Is Withheld in the First Place
Under Internal Revenue Code Section 3405(c), any eligible rollover distribution from an employer plan that is paid to the participant — rather than transferred directly to another qualified plan or IRA — is subject to a flat 20% federal income tax withholding. The withholding is not optional and cannot be waived. The IRS treats it as a prepayment against the tax that would apply if the money were never rolled over.
The rule applies to 401(k), 403(b), and governmental 457(b) plans. It does not apply to distributions from IRAs. A trustee-to-trustee IRA-to-IRA transfer, or a direct rollover from a 401(k) to an IRA or another 401(k), avoids the 20% entirely because the funds never leave the retirement plan system.
The 60-Day Clock and the Full-Amount Redeposit Rule
The withholding sets up a second, more expensive trap. To keep the distribution tax-free, the participant must redeposit the entire pre-withholding amount — not the smaller check they actually received — into a qualified retirement account within 60 days. The clock starts the day after the participant receives the check, according to IRS guidance and Fidelity's rollover documentation.
An example makes the math concrete. A worker requests a $100,000 rollover but tells the plan to make the check payable to them. The plan withholds $20,000 and sends a $80,000 check. To complete a fully tax-free rollover, the participant has 60 days to deposit $100,000 into an IRA. That means finding $20,000 from outside sources to make up the withheld portion. The withheld $20,000 is not lost — it will be credited on the following year's tax return — but it is unavailable during the 60-day window. If the participant only redeposits the $80,000 that arrived, the missing $20,000 is treated as a taxable distribution, plus a 10% early-withdrawal penalty if the participant is under 59½.
The Once-Per-Year IRA Rollover Limit
Even participants who successfully navigate the 60-day rule face a second restriction on the IRA side. The IRS allows only one indirect (60-day) IRA-to-IRA rollover in any 12-month period, aggregated across every IRA the taxpayer owns. A second indirect IRA rollover inside that window is treated as a taxable distribution regardless of whether the 60-day deadline is met. Direct trustee-to-trustee transfers, direct rollovers from employer plans, and Roth conversions do not count against the limit — only participant-received IRA-to-IRA rollovers do.
How to Avoid the Trap
The IRS, Fidelity, Schwab, and Empower all give the same recommendation: request a direct rollover. In a direct rollover, the plan issues the check payable to the new custodian for the participant's benefit — for example, "Fidelity Management Trust Company FBO Jane Smith IRA" — even if the check is physically mailed to the participant to forward. Because the funds are not payable to the participant personally, the 20% withholding does not apply, the 60-day deadline does not start, and the once-per-year IRA limit is not consumed.
Two practical steps close the door on the trap. First, when initiating a rollover, ask the plan administrator to confirm in writing that the payment will be styled as a direct rollover to the receiving custodian. Second, confirm the receiving account is open and coded correctly before requesting the distribution — a delayed or rejected deposit can push the transaction past the 60-day threshold even when the intent was a direct rollover.
Sources: Internal Revenue Service, Fidelity, Empower, Charles Schwab