Net unrealized appreciation (NUA): the company-stock break

Most of what comes out of a traditional 401(k) is taxed the same dull way: as ordinary income, at whatever bracket your other income pushes you into. Pull out a dollar at 65, and the Internal Revenue Service treats it like a paycheck. There is one well-buried exception, and it applies to a specific kind of luck — the employee who spent a career at a company whose stock did well and who held that stock inside the retirement plan. The exception is called net unrealized appreciation, or NUA, and it lives in Internal Revenue Code §402(e)(4) and IRS Notice 98-24.

The mechanics are counterintuitive enough that even competent advisors miss them. Instead of rolling the whole 401(k) into an Individual Retirement Account and being taxed as ordinary income on every withdrawal forever after, you take the employer shares out in kind — the actual stock, moved into a regular taxable brokerage account — and pay ordinary income tax on only what those shares were worth when they first went into the plan. The growth on top rides into the lower world of capital gains. Whether that trade is brilliant or pointless depends entirely on one ratio, and the math is unsentimental about it.

Net unrealized appreciation lets you pull your employer’s company stock out of a 401(k) and pay ordinary income tax on only its cost basis — what it was worth when it entered the plan — rather than its full current value. The appreciation above basis, the NUA itself, is then taxed at long-term capital-gains rates (0/15/20%) when you sell, regardless of how long the shares were actually held, under IRS Notice 98-24. It requires a qualifying lump-sum distribution after a triggering event. NUA wins decisively when the cost basis is low relative to today’s value and you are in a high tax bracket; it is close to worthless otherwise.

How the election actually works

The strategy is not a form you tick on autopilot; it is a sequence with strict conditions, and getting one of them wrong forfeits the entire break. The Internal Revenue Code requires a lump-sum distribution, which has a precise meaning here: the entire vested balance of the plan must be distributed within a single tax year, and the distribution must follow a triggering event — separation from service, reaching age 59½, death, or disability.

Within that single-year window you split the account in two directions. The employer stock goes in kind to a taxable brokerage account. Everything else — the bond fund, the target-date fund, the cash — can be rolled into an IRA the ordinary way, deferring tax as usual. The moment the shares land in the taxable account, you owe ordinary income tax on their cost basis: the value recorded when they were contributed or purchased inside the plan, not their value today. Whether you reach this point through a job change or retirement, the direct-versus-indirect rollover rules for the rest of the balance still apply, so the cash portion should move trustee-to-trustee.

What happens next is the payoff. The net unrealized appreciation — the difference between that cost basis and the market value — does not get taxed as income. It gets taxed as a long-term capital gain when you eventually sell, at the 0%, 15%, or 20% rates that sit well below most ordinary-income brackets. And per Notice 98-24, the NUA qualifies as long-term regardless of how long the shares actually sat in the plan — a one-day-old position still earns the favorable rate on its embedded appreciation.

A worked example: $250,000 of stock, two roads

Consider an employee — call him Marcus — retiring with $250,000 of his company’s stock in his 401(k). When those shares went into the plan over the years, they were worth $50,000. That $50,000 is the cost basis; the remaining $200,000 is net unrealized appreciation. Assume Marcus sits in the 24% ordinary bracket and the 15% long-term capital-gains bracket.

Down the first road, he makes the NUA election. He pays 24% ordinary income tax on the $50,000 basis now — $12,000 — and the $200,000 of appreciation waits. When he later sells the shares, that $200,000 is taxed at 15%, or $30,000. His total tax bill is roughly $42,000.

Down the second road, he does the conventional thing and rolls the entire $250,000 into an IRA. Nothing is taxed today, which feels safer. But every dollar he eventually withdraws is ordinary income. On the original $250,000 alone, at 24%, that is $60,000 — and any further growth inside the IRA is also taxed as ordinary income on the way out.

Approach	Taxed as ordinary income	Taxed at capital gains	Total tax
NUA election (in kind)	$50,000 basis × 24% = $12,000	$200,000 NUA × 15% = $30,000	≈ $42,000
Roll all to IRA, withdraw later	$250,000 × 24% = $60,000	—	≈ $60,000

The $18,000 gap is the prize, and it comes entirely from shifting $200,000 of value out of ordinary-income treatment and into capital-gains treatment. Flip the inputs, though, and the prize vanishes. If Marcus’s basis had been $200,000 against a $250,000 value — only $50,000 of NUA — he would be paying ordinary tax on most of the account up front and shielding almost nothing. The election rewards a low basis relative to value, which is the financial fingerprint of stock that appreciated a great deal.

The caveats that actually bite

The first caveat is the age line. If Marcus were under 59½, the 10% early-withdrawal penalty would apply — but only to the cost basis, the portion taxed as ordinary income at distribution, never to the NUA. On a $50,000 basis that is a $5,000 penalty while $200,000 of appreciation escapes it. The triggering events that unlock NUA often coincide with being past 59½ anyway, but a separation from service in your fifties can drag the penalty in.

The second caveat is what death does to the strategy. Inherited assets normally enjoy a stepped-up basis that erases unrealized gains, and many people assume NUA shares behave the same way. They do not. The net unrealized appreciation is treated as income in respect of a decedent, so it carries over to your heirs, who still owe the capital-gains tax when they sell. The one consolation is that the NUA is not subject to the 3.8% net investment income tax — but the missing step-up means the break is far less generous to an estate than holding ordinary appreciated stock would be.

The third caveat is irreversibility. Once you distribute the shares and make the election, there is no undo. You have voluntarily ended tax-deferred growth on that money in exchange for the basis-versus-NUA split, and if the stock barely appreciated, you have simply pulled retirement savings out of shelter for almost nothing. Because this interacts with concentration risk in a single employer’s stock — the same hazard that shadows restricted stock unit vesting — and because it sits inside a larger sequence of tax-advantaged account decisions, it is genuinely a once-in-a-lifetime decision that usually deserves a certified public accountant’s signature before you pull the trigger.

Who should consider NUA

NUA is a tool with a narrow, sharp purpose, and it earns its place only when two conditions hold at once. The cost basis must be low relative to the stock’s current value — meaning the shares appreciated substantially while inside the plan — and you must be in a high enough ordinary bracket that converting that appreciation to capital-gains treatment saves real money. The long-tenured engineer or executive sitting on company stock worth five times what it cost is the textbook candidate. The employee whose shares barely moved, or who is already in a low bracket, gains little and surrenders deferral for it.

For everyone else, the conventional path remains the right one: roll the whole balance to an IRA, keep it deferred, and manage withdrawals deliberately — perhaps through a Roth conversion ladder that controls which bracket each dollar lands in. NUA is not a default to reach for; it is a precision instrument for a specific lucky problem. Run the basis ratio first, model both roads with your actual brackets, and treat the irreversibility with the respect it demands.

Sources

• Internal Revenue Code §402(e)(4) — the statutory basis for net unrealized appreciation treatment of employer securities in a lump-sum distribution.
• IRS — Notice 98-24 — confirms NUA is taxed at long-term capital-gains rates regardless of the shares’ holding period inside the plan.
• IRS — Topic No. 412, Lump-Sum Distributions — definition of a qualifying lump-sum distribution, triggering events, and the in-kind distribution of employer stock.
• Kitces — Understanding the NUA Rules for Employer Stock — secondary deep-dive on the worked mechanics, basis ratio, and estate-planning edge cases.

This article is educational and not tax advice; NUA elections are irreversible and fact-specific, so confirm your numbers with a qualified CPA or tax advisor before acting.