An executive who spent 20 years accumulating employer stock inside a 401(k) at a $200,000 cost basis, and now holds shares worth $4.2 million, faces a choice that is worth more than $600,000 in federal tax. The gap between those two figures — $4 million — is net unrealized appreciation, or NUA, and the Internal Revenue Code lets it be taxed at long-term capital gains rates instead of ordinary income rates, provided the shares leave the plan as shares.
"The single most expensive mistake is the default answer," said Scott Schwitzer, director of wealth management at Peak American Financial, in a Kiplinger analysis of the provision. "Once the account is rolled into an IRA, the opportunity to save hundreds of thousands is gone for good."
The arithmetic is straightforward. Under standard 401(k) rules, every dollar withdrawn — contributions, employer match and all appreciation — is taxed as ordinary income, a rate that reaches 37% for top earners. On a $4 million distribution, that is roughly $1.5 million owed to the IRS. NUA treatment splits the position into two buckets: the $200,000 cost basis, taxed as ordinary income in the year of distribution, and the $4 million of appreciation, taxed at long-term capital gains rates when the shares are eventually sold. The federal long-term capital gains rate is currently capped at 20%, per the IRS, though higher earners may also owe the 3.8% net investment income tax on other investment income. The NUA portion itself is exempt from that surtax and from the 10% early-withdrawal penalty regardless of the account holder's age.
The election is not automatic, and the eligibility conditions are unforgiving. A triggering event must occur first: separation from the employer, reaching age 59½, disability or death. The entire vested balance across all of that employer's qualified plans must then be distributed within a single calendar year, with no partial distributions carried into the next. The company stock must be transferred in kind — actual shares, delivered into a taxable brokerage account, never sold for cash inside the plan first. The stock must currently sit in a tax-deferred account such as a traditional 401(k); shares held in a Roth 401(k) or Roth IRA do not qualify. And if required minimum distributions were already taken in a prior year, NUA eligibility is lost entirely, though taking only the current year's RMD remains permissible as long as the account is zeroed out by year-end.
The sequencing that decides the outcome
Once eligibility is confirmed, the mechanics require careful ordering. The employer stock is distributed in kind directly into a non-qualified brokerage account, which triggers an immediate ordinary income tax bill on the $200,000 basis alone. Any remaining 401(k) assets — mutual funds, cash, other holdings — can be rolled over tax-free into a traditional IRA or a new employer plan. The $4 million NUA portion then sits untaxed until the shares are sold, at which point it is taxed at long-term capital gains rates no matter how briefly the shares were held after the distribution date. Appreciation that occurs after the distribution is taxed separately, under normal short- or long-term capital gains rules based on the new holding period.
The disqualifiers are where most of the money is lost. Rolling employer stock into an IRA by default permanently forfeits NUA treatment on the entire gain — a common outcome when departing employees do not flag their intent before the rollover paperwork is signed. Taking an RMD in a prior year without realizing it disqualifies future eligibility. Selling shares inside the plan converts NUA to cash and voids the treatment. Failing to distribute the full account balance within one tax year does the same.
Who the math actually favors
NUA works best when the stock is highly appreciated relative to its basis, when the account holder does not need immediate liquidity to cover the upfront ordinary income tax on the basis, and when long-term capital gains rates offer a genuine advantage over the holder's ordinary income bracket. For those under 59½, the trade-off between the 10% early-withdrawal penalty on the cost basis and the long-term tax savings on the gain requires modeling rather than assumption.
The provision applies to employer stock in 401(k) plans, profit-sharing plans and employee stock ownership plans, which means the population it touches is concentrated among long-tenured employees and executives who accumulated shares through matches, ESOP allocations or stock bonus programs. For anyone approaching retirement or a job change with a concentrated, highly appreciated position, the numbers are worth running with a tax professional before the triggering event — not after. The decision is effectively one-way: the in-kind distribution election must be made at the moment of distribution, and the IRS does not offer a second attempt.
This article is for informational purposes only and does not constitute investment advice.