Imagine spending 25 years at a company whose stock price tripled during your career. Your 401(k) now holds $300,000 in employer shares, but the plan only paid $80,000 for them over the decades. If you roll the entire balance into a traditional IRA, every dollar you withdraw later gets taxed as ordinary income, potentially at rates up to 37 percent under the current federal brackets. On $300,000, that could mean a federal tax bill well above $100,000.
Most departing employees never hear about the alternative. A provision in Section 402(e)(4) of the Internal Revenue Code lets you pull employer stock out of the plan, pay ordinary income tax only on the original cost basis ($80,000 in our example), and defer the remaining $220,000 of gain. When you eventually sell the shares, that deferred gain is taxed at long-term capital-gains rates, which sit at 15 percent for the majority of retirees and top out at 20 percent for higher earners (plus the 3.8 percent net investment income tax under IRC Section 1411 for those above the income thresholds). Even accounting for that surtax, the potential savings on $220,000 of gain can easily reach five figures.
The strategy is called net unrealized appreciation, or NUA. It has been in the tax code for decades, yet it remains one of the most underused tools available to workers who retire or leave a company with concentrated stock positions inside their retirement plans.
How NUA works, step by step
While employer shares sit inside a 401(k), all growth is tax-deferred, just like any other plan asset. The plan’s “cost basis” is whatever the plan originally paid for the shares, whether through employer matching contributions, profit-sharing allocations, or employee purchases within the plan.
Think of the process as splitting your 401(k) into two streams on the way out the door. When a participant takes a qualifying lump-sum distribution, the IRS lets them separate the employer stock from everything else in the account. The non-stock portion (cash, mutual funds, bonds) can roll into an IRA as usual. The employer shares move into a regular taxable brokerage account. At that point, only the cost basis of those shares is added to the participant’s taxable income for the year. The net unrealized appreciation, the difference between the stock’s fair market value on distribution day and the plan’s cost basis, is excluded from gross income entirely.
That NUA stays untaxed until the participant sells the shares. When they do, the IRS treats the NUA portion as a long-term capital gain regardless of how long the shares were held after leaving the plan. Any additional appreciation that accrues after the distribution date, however, follows normal holding-period rules: short-term if the shares are sold within a year of distribution, long-term if held longer. IRS Publication 575 walks through these mechanics in its section on lump-sum distributions.
The rules you cannot afford to miss
NUA treatment is not automatic. The distribution must satisfy specific conditions, and missing any one of them disqualifies the entire election.
A triggering event must occur first. The IRS recognizes four: separation from service (for non-self-employed participants), reaching age 59½, total disability (self-employed participants only), or death. You cannot elect NUA simply because you want to rebalance your portfolio.
The entire account must be distributed in a single tax year. This is the rule that trips up the most people. “Lump-sum distribution” under the code means the plan pays out your full vested balance within one calendar year. If you take a partial distribution in December and the rest in January, you have blown the NUA election. The non-stock assets can roll to an IRA and the stock can go to a brokerage account, but everything must leave the plan in the same tax year. One important wrinkle: if you hold balances in multiple sub-accounts under the same employer plan, all of them must be distributed to satisfy the lump-sum requirement.
The cost basis is taxed as ordinary income immediately. If the plan’s cost basis on your employer shares is $80,000, that amount hits your tax return in the year of distribution. Depending on your other income, it could push you into a higher bracket for that year, so timing the distribution carefully matters.
Early-distribution penalties may apply to the basis. If you are younger than 59½ and do not qualify for another exception (such as separating from service in the year you turn 55 or later), the 10 percent early-distribution penalty under Section 72(t) applies to the cost-basis amount. It does not apply to the NUA portion, even if you sell the shares right away.
Tracking the numbers after distribution
When a plan administrator distributes employer securities with NUA, the appreciation appears in Box 6 of Form 1099-R. The IRS instructions for Form 1099-R require payors to report this figure so both the taxpayer and the agency can distinguish the portion taxed now from the portion taxed later.
In practical terms, the NUA equals the fair market value of the employer securities at distribution minus the plan’s cost basis. When shares were acquired at different prices over many years, Treasury Regulation Section 1.402(a)-1(b) permits average-cost methods. Getting the basis number right is critical: it determines how much ordinary income tax you owe up front and how large the deferred capital gain will be.
After distribution, the tracking burden shifts to you. Your brokerage firm will know the market value on the day the shares arrived, but it may not know the plan’s original cost basis or the NUA amount. Keep a copy of your final 1099-R and any plan statements showing historical share-lot detail. When you eventually sell, you will need those records to report the NUA portion correctly on Schedule D.
When NUA saves real money and when it does not
The math favors NUA most clearly when the cost basis is low relative to the current stock price. A participant whose employer stock has a basis of $30,000 and a market value of $250,000 stands to reclassify $220,000 of income from ordinary rates to capital-gains rates. At a 24 percent ordinary rate versus a 15 percent capital-gains rate, that gap is worth roughly $19,800 in federal tax savings alone, and the spread widens further for participants in the 32 or 35 percent brackets.
The case weakens when the basis is high relative to the stock’s value, because there is less appreciation to reclassify. It also weakens for participants in lower tax brackets, where the spread between ordinary and capital-gains rates narrows. Someone in the 12 percent bracket, for instance, may already qualify for a 0 percent long-term capital-gains rate on some or all of the gain, though the ordinary-income hit on the basis could still be meaningful depending on the amount.
State taxes add another layer. States that tax capital gains at the same rate as ordinary income (California and New York among them) reduce the NUA advantage, while states with no income tax (Texas, Florida, and others) leave the full federal benefit intact. Running the numbers with your state’s rates is essential before committing.
Concentration risk is the other side of the equation. Electing NUA means holding a large position in a single stock inside a taxable account. If the company’s share price drops after distribution, the tax benefit can be swamped by investment losses. Participants who are uncomfortable with that exposure may prefer the diversification a full IRA rollover allows, even at a higher eventual tax rate.
A hybrid approach is sometimes the best answer. If a 401(k) holds both employer stock and other investments, the participant can roll the non-stock assets into an IRA and elect NUA only on the employer shares, provided the entire account is emptied in the same tax year. This preserves tax-deferred growth on diversified funds while capturing capital-gains treatment on the appreciated stock.
What happens to NUA shares at death
Estate planning adds a wrinkle that catches many people off guard. Most inherited assets receive a stepped-up cost basis under IRC Section 1014, effectively erasing unrealized gains for heirs. NUA shares are an exception. The NUA portion itself does not receive a step-up at death; it remains taxable as a long-term capital gain to the beneficiary when the shares are sold, because it is treated as income in respect of a decedent under IRC Section 691. Only the post-distribution appreciation (the gain that accrued after the shares left the plan) qualifies for the step-up.
This means that for participants whose primary goal is passing wealth to heirs rather than spending it down, a full IRA rollover may actually produce a better after-tax result. The comparison depends on the size of the NUA, the participant’s life expectancy, and the beneficiary’s tax bracket, all of which a tax adviser can model before the distribution deadline.
Why the strategy stays under the radar
Plan administrators are not required to proactively advise departing employees about the NUA election. No federal regulation mandates that the option appear in rollover paperwork or exit counseling materials. A 2013 Government Accountability Office report on 401(k) rollovers found that many participants received limited or no guidance about distribution alternatives beyond a direct IRA transfer, and nothing in the regulatory landscape has changed materially since then.
Recordkeeping gaps compound the problem. When a plan has changed custodians or merged with another plan over the years, historical share-lot data can be incomplete. The Treasury regulation allows for averaging, but the practical accuracy depends on data quality that varies widely from one plan to the next. Workers with complex purchase histories may find the basis calculation less straightforward than the statute implies.
The result is a provision that offers measurable tax savings to a specific group of retirees, yet remains largely invisible to the people it was designed to help. The rules are settled law, not a loophole or a gray area. They appear in the statute, the regulations, and the IRS’s own reporting forms. For workers with significant employer stock in their 401(k), the single most valuable step before signing rollover paperwork is asking a tax adviser to run the NUA numbers. The conversation takes an hour. The savings can last a lifetime.
