How a 401(k) Rollover to an IRA Works

A 401(k) is an employer-sponsored plan governed by ERISA and administered by a plan administrator chosen by the employer. An IRA is an individual account opened directly with a financial institution — a brokerage, a bank, or an insurer — and governed primarily by IRS rules under the Internal Revenue Code. When assets move from one to the other, the transaction is called a rollover, and the IRS treats it as a continuation of the same tax-deferred (or tax-free, in the Roth case) status rather than a distribution, provided specific procedural rules are followed.

This piece covers the mechanical sequence of a rollover from a traditional 401(k) into a traditional IRA — the two most common account types in this transaction. The tax treatment of the destination account, which differs meaningfully between traditional and Roth IRAs, is a separate subject; how traditional and Roth IRA tax treatment differs is covered elsewhere on this desk.

The Step-by-Step Mechanics of Moving 401(k) Assets to an IRA

The IRS recognizes two procedural paths for a rollover: the direct rollover and the 60-day (indirect) rollover. These are not interchangeable in their tax consequences.

Direct rollover. In a direct rollover, the plan administrator of the 401(k) transfers funds directly to the IRA custodian — either by wire or by a check made payable to the IRA custodian for the benefit of the account holder, not to the account holder personally. Because the account holder never takes constructive receipt of the funds, no mandatory withholding applies and no taxable distribution is triggered. The IRS treats the entire transferred amount as continuing its tax-deferred status. The plan administrator reports the transaction on Form 1099-R using distribution code G, which signals a direct rollover.

60-day (indirect) rollover. In an indirect rollover, the plan administrator issues a check or wire payable directly to the account holder. At that moment, the IRS treats the event as a distribution. Federal law requires the plan to withhold 20 percent of the taxable amount for federal income tax. The account holder then has 60 calendar days from the date of receipt to deposit the funds — including the withheld 20 percent, which must be made up from other funds — into a qualifying IRA. If the full pre-withholding amount is not deposited within 60 days, the shortfall is treated as a taxable distribution for that calendar year and, if the account holder is under age 59½, is also subject to the 10 percent early distribution penalty under IRC Section 72(t).

The one-rollover-per-year rule. The IRS limits IRA-to-IRA rollovers to one per 12-month period across all of an individual's IRAs combined. However, this limit applies to IRA-to-IRA rollovers, not to rollovers from employer plans like a 401(k) into an IRA. A 401(k)-to-IRA rollover is not counted against the IRA one-per-year limit. The governing IRS guidance on this distinction is Publication 590-A.

Why assets move from a 401(k) to an IRA. The question of why this transaction occurs at all is rooted in plan structure. A 401(k) plan exists only in connection with an employer. When employment ends — whether through a job change, layoff, or retirement — the former employee is generally no longer eligible to make new contributions, and the plan may impose restrictions or fees that do not apply to an IRA. The rollover rules that apply after a job change describe the specific timelines and options a departing employee faces. An IRA, by contrast, is portable and not tied to any employer relationship.

Roth 401(k) assets. If the 401(k) contains a designated Roth account — meaning after-tax contributions — those assets must roll into a Roth IRA, not a traditional IRA, to preserve their tax-free treatment. Rolling Roth 401(k) assets into a traditional IRA would convert them to pre-tax status, which is not permitted. The plan administrator is required to separately account for Roth and pre-tax balances on the distribution paperwork.

Employer stock (net unrealized appreciation). If the 401(k) holds employer stock, a special tax rule called net unrealized appreciation (NUA) may apply. Rolling employer stock into an IRA forfeits the potential NUA treatment, under which the appreciation on the stock would otherwise be taxed at long-term capital gains rates rather than ordinary income rates. Once the stock is inside an IRA, all future distributions are taxed as ordinary income regardless of how the underlying investment performs.

Who Administers Each Side of the Rollover Transaction

On the sending side, the 401(k) plan administrator — typically a financial institution or third-party administrator contracted by the employer — holds the assets in trust for plan participants. The plan administrator is responsible for issuing the distribution, applying mandatory withholding where required, and filing Form 1099-R with the IRS. The employer itself does not typically handle the mechanics of the distribution, but the employer selects the plan administrator and establishes the plan document that governs what rollover options are available. It is worth noting that employer contributions may be subject to a vesting schedule, meaning only the vested portion of an employer match is eligible for rollover; unvested amounts are forfeited and cannot be transferred.

On the receiving side, the IRA custodian — a bank, brokerage, or other IRS-approved institution — accepts the incoming funds and opens or credits the IRA account. The IRA custodian does not file a Form 5498 reporting the rollover contribution until after the tax year closes, which means the rollover may appear on the account holder's IRS records on a different schedule than the outgoing 1099-R from the plan administrator.

Neither the plan administrator nor the IRA custodian determines whether the rollover is taxable — that determination is made by the IRS based on the procedural path taken and the information reported on Form 1099-R and Form 5498. The account holder is responsible for reporting the rollover correctly on Form 1040, including entering the gross distribution amount and the taxable amount (zero, if a qualifying direct rollover) on the appropriate lines.

Where Rollovers Produce Unexpected Tax Results

The withheld 20 percent trap. The most common unexpected result in an indirect rollover occurs when the account holder deposits only the net check amount — the 90 percent after withholding — into the IRA within the 60-day window, without making up the withheld 20 percent from other funds. The IRS treats the missing 20 percent as a distribution received and not rolled over. That amount is included in gross income for the year and, if applicable, is subject to the early distribution penalty. The withheld amount may eventually be recovered as a tax refund if the account holder's total withholding exceeds tax owed, but the income inclusion itself is not reversed.

The 60-day deadline and hardship waivers. The 60-day window is a hard deadline. Missing it — even by one day — converts the entire indirect rollover into a taxable distribution unless the IRS grants a waiver. Waivers are available under specific circumstances (such as a financial institution error or a casualty event), but they require a private letter ruling or a self-certification procedure under Revenue Procedure 2016-47. The waiver process is administrative, not automatic.

After-tax contributions inside the 401(k). Some 401(k) plans allow after-tax (non-Roth) contributions. These have a cost basis — they were taxed before going in. When rolled to a traditional IRA, the after-tax basis carries over and is tracked using Form 8606. If the after-tax basis is not properly tracked and reported, future IRA distributions will be taxed in full, effectively taxing the same dollars twice. The IRS does not automatically track basis; the account holder's Form 8606 filings are the record.

Does Medicare "roll over"? A common search question conflates the word "rollover" across Medicare and retirement accounts. Medicare does not use a rollover mechanism. Medicare Part A and Part B coverage is not an account with a balance; it is an insurance program administered by the federal government. There is no Medicare balance to transfer, carry forward, or roll into another account. The term "rollover" has no application to Medicare enrollment or coverage. Separately, a large IRA or 401(k) distribution in the year of a rollover could increase modified adjusted gross income, which affects Medicare Part B premium calculations under the income-related adjustment (IRMAA) — but that is a consequence of a taxable distribution, not of a qualifying rollover itself.

Capital gains inside a traditional IRA. Another frequent question is whether capital gains inside a traditional IRA are taxed at capital gains rates. They are not. Once assets are inside a traditional IRA, all investment growth — including what would otherwise be long-term capital gains — loses its preferential rate character. All distributions from a traditional IRA are taxed as ordinary income, regardless of what generated the growth. This is distinct from a taxable brokerage account, where holding periods determine the rate applied. The NUA exception noted above is the only scenario in which capital gains treatment survives a distribution from a retirement plan, and it applies only to employer stock distributed in kind — not to assets rolled into an IRA.

What the Paperwork Shows — and What It Does Not

Form 1099-R from the plan administrator. The plan administrator issues Form 1099-R to both the account holder and the IRS by January 31 of the year following the distribution. Box 1 shows the gross distribution amount. Box 2a shows the taxable amount; for a direct rollover, this is typically zero. Box 7 shows the distribution code: code G for a direct rollover to an IRA or another qualified plan. The form does not show what happened to the money after it left the plan — it does not confirm that the IRA custodian received it.

Form 5498 from the IRA custodian. The IRA custodian reports rollover contributions on Form 5498, filed with the IRS by May 31 of the year following the contribution. Box 2 shows the rollover amount received. This form is issued after the tax filing deadline for most individuals, so it is not available when the Form 1040 is prepared. The account holder must report the rollover on the tax return based on their own records and the 1099-R, not by waiting for the 5498.

What the IRA statement does not show. The IRA account statement from the custodian shows the current balance, investment holdings, and transaction history within the IRA. It does not show the tax basis of after-tax contributions (that is tracked on Form 8606), it does not show the original source of the funds (whether from a rollover or a regular contribution), and it does not show the vesting history of employer contributions that were rolled in. The statement is an asset record, not a tax record.

The mechanics of a 401(k)-to-IRA rollover are defined almost entirely by IRS procedural rules — specifically, whether the transfer qualifies as a direct rollover or is treated as a distribution — and the tax consequences follow automatically from which path the transaction takes, not from any election made at a later date.

Note: This explains how a retirement system works. It is not financial, tax, or legal advice, it is not specific to any individual's retirement, and it is not a substitute for a licensed financial, tax, or legal professional. Rules, ages, and dollar limits change by year — check the cited sources.