Company Stock in a 401(k) Gets a Special Tax Break. One Standard Rollover Erases It Forever.

Company stock held inside a 401(k) sits in an unusual corner of the tax code. When an employee separates from service or reaches retirement age, the shares can leave the plan under a rule that treats them differently from every other dollar in the account. The rule is called Net Unrealized Appreciation, or NUA.

It converts most of the gain on those shares from ordinary income into long-term capital gain. A routine rollover to an IRA, the default path for most departing employees, extinguishes that treatment. Once the shares land in an IRA, the tax break is gone and cannot be recovered.

How the NUA Rule Works

Inside a 401(k), employer stock has two components: the cost basis (what the plan paid for the shares) and the appreciation on top of that basis. NUA allows the participant to distribute the shares in kind to a taxable brokerage account. Ordinary income tax is owed only on the cost basis in the year of the distribution. The appreciation is taxed at long-term capital gains rates when the shares are eventually sold, regardless of holding period at that point.

The tax rate spread is the entire reason the strategy exists. Ordinary income tax brackets top out at 37%, while long-term capital gains max out at 20%, with a 15% bracket covering most middle-income retirees and a 0% bracket at the bottom. Shares rolled into an IRA lose that split. Every future dollar withdrawn, basis and gain alike, comes out as ordinary income.

The Conditions That Must Be Met

NUA has specific requirements. The Internal Revenue Code requires a lump-sum distribution, meaning the entire balance of the 401(k) must be distributed within a single calendar year, following a triggering event: separation from service, reaching age 59½, disability, or death. The employer shares must be transferred in kind to a taxable account.

Cash or non-employer assets in the plan can be rolled into an IRA in the same transaction, but the stock itself cannot be transferred to the IRA first. A partial distribution, or a rollover followed by a subsequent attempt to withdraw the stock, permanently disqualifies the treatment.

Where the Math Tilts

The strategy works best when the cost basis sits low relative to current value. Take an employee who accumulated shares over decades at an average basis of $20 per share, now worth $200. That person would pay ordinary income tax on the $20 basis at distribution and long-term capital gains on the $180 gain when sold.

Those same shares rolled into an IRA would generate ordinary income on the full $200 at withdrawal. When the basis is high relative to market value, the calculation flips, and a rollover often delivers a better outcome. Inflation only compounds the stakes.

The Consumer Price Index reached 332.6 in June 2026, up from 323.3 a year earlier, and retirees drawing from tax-deferred accounts feel that erosion directly, since every dollar of ordinary income withdrawn gets taxed before it can be spent.

Concentration Risk on the Other Side

The tax break sits alongside a separate problem: concentration. Consumer expenditures averaged $78,535 per household in 2024, and a retirement plan tied heavily to a single employer’s stock can swing sharply against those spending needs. Long-time radio host Clark Howard has said: “Company stock terrifies me.

If you do company stock, do it for sentimental reasons and don’t make it any more than 10% of the money in your 401k.” NUA changes the tax character of an existing position without addressing concentration itself.

The Point of Decision

The rollover paperwork arrives at the time of separation, often bundled with plan-closing forms. Signing it moves everything, including employer shares, into an IRA in a single step. That step is irreversible for NUA purposes. The special tax treatment attaches to the shares only while they remain in the qualified plan and only through a properly executed lump-sum distribution.

Once the shares are held in an IRA, the code offers no path back. For anyone holding appreciated employer stock, the question of whether to separate those shares from the rest of the balance has to be answered before the rollover is signed, not after.

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