How a $1.6 Million 401(k) With Concentrated Stock Can Dodge the Tax Trap Most Executives Miss

A Reddit thread in r/Fire earlier this year followed a laid-off medical-device VP staring at a $480,000 severance offer and a 401(k) stuffed with employer stock she had accumulated over 22 years. Her question was the same one every senior operator asks when a termination letter lands: how do I keep the IRS from taking a third of my payout, and what do I do with the company shares sitting inside my retirement plan?

The answer for her, and for a hypothetical 56-year-old executive we will call Diane, was Net Unrealized Appreciation (NUA), a rarely used 401(k) provision that turns ordinary income into long-term capital gains at the moment of separation and is often overlooked in favor of a Roth conversion or the Rule of 55.

The Setup: Severance, Company Stock, and a Closing Window

Diane, 56, was let go in a restructuring. Her package: $480,000 in severance paid across 2026, pushing her taxable income into the 35% federal bracket that begins at $256,225 for single filers. Her 401(k) held $1.6 million, of which $700,000 was employer stock she had bought inside the plan for a cost basis of $140,000. The remaining $560,000 was pure appreciation.

The default move (the one most departing executives make) is to roll the entire 401(k) into an IRA. Simple, tidy, and it turns every future dollar withdrawn (including that $560,000 of company-stock gain) into ordinary income. At a blended 32% to 35% marginal rate during her drawdown years, that appreciation would eventually cost her north of $180,000 in federal tax.

How NUA Rewires the Math

NUA lets Diane distribute the employer stock in kind to a taxable brokerage account as part of a lump-sum distribution in the year she separates from service. The trigger requires that the entire 401(k) balance be distributed within one tax year, with the company shares going to a taxable account and everything else rolling to an IRA.

The tax treatment splits into three parts:

1. Cost basis is taxed as ordinary income now. Diane pays tax on the $140,000 basis in 2026. At her 35% marginal rate, that is roughly $49,000 out of pocket this year. Painful, but it is the price of admission.
2. The $560,000 of appreciation becomes long-term capital gains. It does not matter how long she held the shares inside the plan. NUA is automatically long-term. When she eventually sells, the gain is taxed at 0%, 15%, or 20% depending on her income that year.
3. She controls the timing of the gain. Once retired and living on cash plus taxable brokerage assets, her ordinary income drops. Selling into the 15% long-term capital gains bracket, which runs to $545,500 of taxable income for single filers in 2026, is realistic.

Compare the two paths on the $560,000 of appreciation alone. Rolled into an IRA and withdrawn at a 35% ordinary rate, the tax bill is $196,000. Distributed via NUA and later sold at 15% long-term capital gains, the tax bill is $84,000. The difference is $112,000, and that is before considering that NUA shares held until death receive a step-up in basis on the appreciation accrued after distribution.

Where the Strategy Bites Back

NUA carries real costs. The lump-sum requirement is unforgiving: miss the same-year rule, take a partial rollover the wrong way, or roll the stock into an IRA first, and the election is permanently lost. The basis tax is due immediately, which stings in a severance year already inflated by a $480,000 payout. And concentrated company stock carries real single-stock risk once it sits in a taxable account outside the plan.

The strategy also assumes a meaningful spread between the cost basis and the market value. As a rough filter, NUA rarely justifies the paperwork unless appreciation exceeds 50% of the position and the shares represent at least six figures.

Three Moves Before You Sign the Separation Agreement

1. Request a cost-basis breakdown of employer securities from the plan administrator in writing. The number determines whether NUA is worth pursuing, and plans do not volunteer it.
2. Confirm with HR that severance will not be paid into the following tax year in a way that blocks a same-year lump-sum distribution. The NUA election dies if the 401(k) is not fully emptied by December 31 of the separation year.
3. If combined income in the severance year crosses the 32% bracket at $201,775 for single filers, a fee-only CPA who has actually processed an NUA distribution is worth the retainer. The election is one-shot and irreversible.

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