How Does Net Unrealized Appreciation Cut Your 401(k) Tax? (w/Examples) + FAQs

This article reflects federal rules as of June 2026 and covers tax year 2025 (the 2026 filing season), with 2026 figures noted where finalized. State rules vary and are addressed separately below. Tax law changes — confirm current figures with IRS.gov before you act. This guide is educational and is not a substitute for advice from a licensed CPA, tax attorney, or financial planner for your own situation.

Quick Answer

Net Unrealized Appreciation (NUA) lets you pay ordinary income tax on only the cost basis of employer stock inside your 401(k), then pay the lower long-term capital gains rate on all the growth when you sell. For tax year 2025, that gap can save you 10–20 percentage points of tax on the gain.

What This Means for Your Money

Most money that leaves a 401(k) is taxed as ordinary income — the same high rate as your paycheck. But if your plan holds shares of your own employer’s company stock that have grown a lot, a special rule in IRC Section 402(e)(4) lets you split that stock into two pieces and tax each piece differently. You pay ordinary income tax on the small piece (what the shares originally cost), and the big piece (the appreciation) gets the gentler long-term capital gains rate. The immediate consequence of missing this election is simple: you may hand the IRS tens of thousands of dollars more than you had to.

The catch is that NUA is fragile and one-shot. You must move the entire plan balance out in a single tax year after a qualifying event, and one wrong step — a partial withdrawal, an accidental dividend payout, a missed deadline — can erase the benefit for good. According to Vanguard’s How America Saves report, a meaningful share of large 401(k) plans still hold employer stock, so this is a live decision for many retirees right now.

Here is what you will learn:

💡 How the NUA “tax split” works in plain English, with the exact formula
🧮 Three fully worked dollar examples comparing NUA against a plain IRA rollover
⚠️ The triggering events, the lump-sum rule, and the deadlines that make or break it
🚫 Seven costly mistakes that quietly destroy the tax break
🗺️ A decision aid so you can tell whether NUA is right for you

Net Unrealized Appreciation, Deconstructed

NUA is the growth in your employer’s stock while it sat inside your retirement plan, measured from what you paid for it to its value on the day it leaves the plan. The IRS defines it as the fair market value of the shares at distribution minus the plan’s cost basis in those shares.

The core formula

The math has two layers, and each one matters. The first layer is the basis, which is taxed now as ordinary income:

Cost basis = what the plan paid for the shares (the price when they were bought inside the 401(k)).
NUA = Fair Market Value at distribution − Cost basis.

The plain-English version: if the plan bought your company shares for $20,000 and they are worth $120,000 when you take them out, your basis is $20,000 and your NUA is $100,000. The $20,000 is taxed today like salary. The $100,000 waits and is taxed later at long-term capital gains rates — no matter how long you held the shares inside the plan. The consequence of getting this number wrong is real: your plan, not you, sets the official basis, and it appears on your Form 1099-R. A common misconception is that NUA depends on your personal holding period — it does not; the NUA portion is automatically long-term. What you should do: ask your plan administrator for a written breakdown of your per-share cost basis before you do anything else.

The three tax buckets

When you finally sell NUA shares, the IRS sorts your money into three buckets, and each is taxed differently. This is the heart of the strategy.

Bucket 1 — Cost basis: taxed as ordinary income in the year of the distribution.
Bucket 2 — The NUA itself: taxed at the long-term capital gains rate when you sell, regardless of how long you actually held it.
Bucket 3 — Growth after distribution: any gain above the distribution-day value is taxed at long-term or short-term capital gains rates depending on how long you held the shares after they left the plan.

The consequence of confusing these buckets is overpaying. For example, if you sell within a year of distribution, Bucket 3 gain is short-term (ordinary rates), but Bucket 2 — the original NUA — still gets the favorable long-term rate. Your next step is to track your distribution date carefully, because it starts a brand-new holding clock for Bucket 3.

Why NUA Cuts Your Tax: The Rate Gap

The whole benefit comes from one number: the difference between your ordinary income tax rate and your long-term capital gains rate. For tax year 2025, ordinary federal rates run up to 37%, while long-term capital gains top out at 20%.

The 2025 long-term capital gains brackets are:

Filing status	Long-term capital gains rate
Single, taxable income up to $48,350	0%
Single, $48,351 to $533,400	15%
Single, over $533,400	20%
Married filing jointly, up to $96,700	0%
Married filing jointly, $96,701 to $600,050	15%
Married filing jointly, over $600,050	20%

If your appreciation would otherwise be taxed at a 32% ordinary rate but instead gets the 15% long-term rate, you keep 17 cents more of every appreciated dollar. On $100,000 of NUA, that is $17,000 saved. High earners should also note the extra 3.8% Net Investment Income Tax, which applies once modified adjusted gross income tops $200,000 (single) or $250,000 (married filing jointly) for 2025 — it can apply to the NUA gain when sold, so the true capital gains cost may be 18.8% rather than 15%.

The Rules That Make NUA Work

NUA is not automatic. You must satisfy three strict federal requirements, and failing any one of them turns your entire stock distribution into ordinary income. The rules come from IRC Section 402 and IRS guidance.

Rule 1 — A qualifying triggering event

You can only use NUA after one of four triggering events: separation from service (you leave the employer), reaching age 59½, total and permanent disability, or death. The consequence of acting without a trigger is that no lump-sum treatment exists, so NUA is off the table. For example, an employee who is still working at the company and is only 50 cannot use NUA unless the plan allows an in-service distribution at 59½. A common misconception is that simply retiring later resets the clock — it does not; what matters is that a trigger has occurred and that you have not taken any distributions since. Your move: confirm in writing which trigger applies to you and the date it occurred.

Rule 2 — A lump-sum distribution within one tax year

You must distribute your entire vested balance from all like plans of that employer within a single calendar year, and the employer stock must go in-kind to a taxable brokerage account. The consequence of breaking this rule is severe: a partial distribution, or a stray withdrawal in a prior year, disqualifies the lump sum and the NUA benefit vanishes. According to napa-net’s analysis of lump-sum triggers, the balance must be zeroed out by December 31 of the distribution year. You can still roll the non-stock assets into an IRA while sending only the company shares to a brokerage account. The next step: coordinate the timing with your administrator so everything clears before year-end.

Rule 3 — Employer securities only

NUA applies only to actual shares of your employer’s stock (or a parent/subsidiary), not to mutual funds, target-date funds, or cash holding company stock indirectly. The consequence of misidentifying the holding is claiming NUA on assets that do not qualify, which the IRS will reject. For instance, a fund that invests in your employer does not count — only directly held employer securities do. A frequent misconception is that any “company” investment qualifies. What to do: verify on your statement that you hold the actual ticker, not a fund.

Which Situation Applies to You?

NUA is powerful for some people and a trap for others. Use this branch to find your path before reading the examples.

You are 55+ and separated from service, with a low basis and high appreciation: NUA is likely a strong fit; you avoid the 10% penalty and capture the rate gap. Read the Maria example below.
You are under 55 and leaving your job: the 10% early-distribution penalty hits the basis portion — proceed only if the appreciation is large enough to outweigh it. Read the David example.
Your stock has high basis and modest appreciation (over ~30% basis): a plain IRA rollover usually wins; NUA’s upfront tax bill often eats the benefit. Read the Priya example.
You inherited employer stock in a 401(k): NUA can carry over to you as the beneficiary, but it is “income in respect of a decedent” and gets no full step-up — see the FAQs.
You live in a high-tax state like California or New York: the state angle below changes your math.

Worked Example 1 — NUA Beats the Rollover

Meet Maria, age 62, recently retired, single, with a $300,000 taxable income year ahead. Her 401(k) holds company stock worth $500,000 with a $50,000 cost basis, so her NUA is $450,000.

If Maria elects NUA, she pays ordinary income tax on the $50,000 basis now. At roughly a 24% effective rate that is $12,000. When she later sells the shares, the $450,000 NUA is taxed at the 15% long-term capital gains rate (her income sits below the 20% threshold), costing $67,500. Her total federal tax is about $79,500.

If instead she rolls the whole thing to a traditional IRA and later withdraws it, every dollar — all $500,000 — is eventually taxed as ordinary income. At a blended 30% rate that is $150,000. NUA saves Maria roughly $70,500. The lesson from Forbes’ NUA breakdown holds: a low basis plus large appreciation is the ideal NUA profile.

Maria’s choice	Estimated federal tax
NUA election	~$79,500 (split: $12,000 ordinary + $67,500 capital gains)
Full IRA rollover	~$150,000 (all ordinary income over time)

Worked Example 2 — The Under-55 Penalty Trap

Meet David, age 52, who just left his employer. His 401(k) holds company stock worth $200,000 with an $80,000 basis, giving him $120,000 of NUA.

Because David is under 55 and separated from service before that age, the 10% early-distribution penalty applies to his $80,000 basis: an extra $8,000 on top of ordinary income tax. If his ordinary rate is 24%, the basis costs $19,200 in tax plus the $8,000 penalty, or $27,200 before he even sells. He then owes 15% on the $120,000 NUA when he sells — $18,000.

David’s NUA still beats a full rollover in pure rate terms, but the penalty narrows the gap sharply, and his 40% basis ratio is high. For David, waiting until age 55 to separate — or rolling to an IRA — may be the smarter call. As Greenbush Financial notes, separating after reaching 55 removes the penalty entirely.

David’s penalty exposure	Cost
10% penalty on $80,000 basis (under 55)	$8,000
Same distribution if separated at 55+	$0 penalty

Worked Example 3 — When the Rollover Wins

Meet Priya, age 60, single, whose 401(k) stock is worth $250,000 with a $175,000 basis — a 70% basis ratio and only $75,000 of NUA.

If Priya elects NUA, she pays ordinary tax on $175,000 now, which can push her into the 32% bracket and trigger about $56,000 in immediate tax, all in one year. The $75,000 NUA later costs 15%, or $11,250. Her large upfront bill, plus losing decades of tax deferral, makes NUA painful here.

A traditional IRA rollover lets Priya defer all tax, spread withdrawals across many lower-bracket years, and keep her money compounding. When basis is a big share of value, the rollover usually wins — the RSM analysis of the NUA election confirms that a low basis-to-value ratio is what drives the benefit.

Priya’s choice	First-year tax hit
NUA election	~$56,000 ordinary tax now on $175,000 basis
Full IRA rollover	$0 now; taxed gradually as withdrawn

The Process and Forms, Step by Step

Executing NUA correctly is a sequence, and order matters. Here is the federal mechanic from event to sale.

Confirm your triggering event and basis. Get a written cost-basis statement from your plan administrator.
Open a taxable brokerage account to receive the shares in-kind (not a sale, an actual share transfer).
Request a lump-sum distribution of the entire vested balance within one calendar year. Send the employer stock in-kind to the brokerage account; the rest can roll to an IRA.
Receive Form 1099-R. The taxable basis appears in Box 2a, and the NUA amount appears in Box 6.
Report the basis as ordinary income on your Form 1040 for the distribution year.
When you sell, report the gain on Form 8949 and Schedule D, with the NUA always treated as long-term.

Because in-kind share transfers have no automatic tax withholding, you must raise your other withholding or pay estimated tax to avoid an underpayment penalty. The deadline that controls everything is December 31 of the distribution year — miss it and the lump-sum status fails. DIY is possible for simple cases, but a CPA or fee-only planner (typically $1,500–$5,000 for this kind of analysis) is worth it when six figures are at stake.

Federal vs. State: Does Your State Tax NUA?

Federal law sets the NUA framework, but your state may or may not follow it. Most states that have an income tax start from federal adjusted gross income, so they generally respect the federal split — but the capital gains rate is where states diverge sharply.

Issue	Federal rule	State reality
Long-term capital gains rate	0%, 15%, or 20% for 2025	Many states tax capital gains as ordinary income with no preferential rate
No-income-tax states (FL, TX, WA*, NV, etc.)	Federal tax still applies	No state tax on the NUA gain at all
High-tax states (CA, NY, NJ)	Federal preferential rate applies	California taxes capital gains as ordinary income up to 13.3%, erasing much of the state-level edge

Washington is an asterisk because it imposes a 7% tax on certain long-term capital gains above an annual threshold, even though it has no general income tax. The consequence of ignoring state law is a surprise bill: a Californian celebrating the federal rate gap may find the state claws much of it back. Your next step is to check your state revenue department’s treatment of capital gains before you sell, and consider whether moving the sale to a lower-tax year helps.

Mistakes to Avoid

Each of these errors has wrecked an otherwise valid NUA election.

Taking a partial distribution first. Any prior withdrawal in the same period can disqualify the lump sum, converting all gain to ordinary income.
Rolling the stock into an IRA by mistake. Once company shares land in an IRA, NUA is permanently lost and all gain becomes ordinary income.
Separating at age 54 and distributing at 55. You did not separate after 55, so the 10% penalty still applies to the basis.
Missing the December 31 lump-sum deadline. Spreading the distribution across two tax years voids the election.
Forgetting withholding. No tax is withheld on in-kind shares, leading to underpayment penalties at filing.
Holding a single concentrated stock too long. Chasing the tax break can leave you over-exposed if the company stock crashes.
Ignoring the Net Investment Income Tax. High earners may owe an extra 3.8%, making the real rate 18.8% rather than 15%.

Do’s and Don’ts

Do get your per-share cost basis in writing first — the whole strategy depends on it.
Do open the taxable brokerage account before requesting the distribution, so shares transfer in-kind.
Do run a basis-to-value ratio; under ~25% favors NUA, over ~30% often favors a rollover.
Do consider diversifying out of the stock after distribution to manage concentration risk.
Do pay estimated tax on the basis to dodge underpayment penalties.
Don’t let any company shares touch an IRA, ever.
Don’t take a partial withdrawal before the lump sum, because it can disqualify everything.
Don’t assume your state grants a capital gains break — many tax it as ordinary income.
Don’t forget the NUA shares get no full step-up at death (income in respect of a decedent).
Don’t go it alone on a six-figure decision; a pro’s fee is small next to a wrong election.

Pros and Cons

Pro — Lower tax on growth, because appreciation is taxed at capital gains rates, not ordinary rates.
Pro — Immediate access to the shares in a taxable account with no future RMDs on that money.
Pro — Lower lifetime RMDs, since moving stock out shrinks the IRA balance subject to required distributions.
Pro — Flexibility to sell over time and control which years the capital gains land in.
Pro — Charitable leverage, since donating appreciated NUA shares can sidestep the capital gains entirely.
Con — Upfront ordinary tax on the basis in a single year, which can spike your bracket.
Con — Concentration risk from holding one company’s stock outside the plan.
Con — 10% penalty on the basis if you are under 55 at separation.
Con — Irreversible and fragile, because one misstep destroys the benefit.
Con — No full step-up at death on the NUA portion, unlike most inherited assets.

What to Do Next

If you are weighing NUA right now, take these steps in order before any money moves.

Confirm your triggering event and get a written cost-basis statement from your plan administrator this week.
Calculate your basis-to-value ratio; if it is under about 25%, NUA likely helps — over 30%, lean toward a rollover.
Check your age: if you are under 55 and separating, factor in the 10% penalty on the basis.
Open a taxable brokerage account to receive shares in-kind.
Confirm your state’s capital gains treatment with your state revenue agency.
Call a CPA or fee-only planner before December 31 to model both paths and execute the lump sum on time.

Frequently Asked Questions

Does NUA apply to all 401(k) money? No. NUA applies only to actual shares of your employer’s stock held in the plan. Cash, mutual funds, and target-date funds get no NUA treatment and are taxed as ordinary income when distributed.

What tax rate applies to the NUA portion? The long-term capital gains rate — 0%, 15%, or 20% for 2025 depending on your income — applies to the NUA when you sell, regardless of how long you held the shares.

Is the cost basis taxed right away? Yes. The basis is taxed as ordinary income in the year of the lump-sum distribution. The appreciation (NUA) is deferred until you actually sell the shares.

What is the deadline to complete an NUA distribution? December 31 of the distribution year. Your entire vested plan balance must be distributed within one tax year, or the lump-sum requirement fails and NUA is lost.

Does the 10% early-distribution penalty apply? Yes, if you are under 55 and separated from service before that age — but only on the basis, not the NUA. Separating from service during or after the year you turn 55 avoids it.

Can I roll the non-stock assets into an IRA? Yes. You can send the company shares in-kind to a taxable brokerage account for NUA treatment while rolling the remaining plan assets into a traditional IRA tax-free.

Does my state give NUA the capital gains break? It depends. Most income-tax states follow the federal split, but many tax capital gains as ordinary income with no preferential rate, while no-income-tax states like Florida tax it at 0%.

What form reports the NUA amount? Form 1099-R, Box 6 reports the NUA. The taxable basis appears in Box 2a, and you report sales later on Form 8949 and Schedule D.

Is there extra tax beyond capital gains? Yes, possibly. High earners may owe the 3.8% Net Investment Income Tax on the gain once MAGI exceeds $200,000 (single) or $250,000 (married filing jointly) for 2025.

Do heirs get a step-up in basis on NUA shares? No, not fully. The NUA portion is income in respect of a decedent and does not receive a step-up; only appreciation above the NUA value at death gets stepped up.

Can I undo an NUA election after the fact? No. The election is generally irreversible once executed. That is why modeling both NUA and a rollover before acting is essential.

Is NUA worth it if my basis is high? Usually no. When basis is a large share of value — roughly over 30% — the upfront ordinary tax often outweighs the capital gains savings, and a plain IRA rollover tends to win.

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