Employer Stock in a 401(k): Tax Implications and How to Minimize Them

Most employees with highly appreciated company stock in a 401(k) default to rolling it into an IRA when they retire — a choice that silently converts decades of gains into ordinary income taxed at up to 37%. There is an alternative: the Net Unrealized Appreciation (NUA) election, which can reduce the effective tax rate on that appreciation to 15–20%. For a $1M position with a $100K cost basis, the difference can exceed $160,000 in lifetime taxes. Here's how the tax math works — and the strategies that change it.

Why employer stock is taxed differently than other 401(k) assets

In a traditional 401(k), contributions go in pre-tax and everything comes out as ordinary income — bonds, mutual funds, target-date funds, and everything else. There is no capital gains treatment for any of those assets, regardless of how much they've appreciated inside the account.

Employer stock is the exception. IRC § 402(e)(4) — the Net Unrealized Appreciation provision — gives qualifying employees the ability to distribute employer stock in-kind (as shares, not cash) to a taxable brokerage account. When that happens:

• You pay ordinary income tax only on the cost basis — the amount the plan originally paid for the shares on your behalf.
• The appreciation — the difference between cost basis and market value at distribution — is treated as long-term capital gain when you sell, regardless of how long you hold the shares after distribution.

This means the same stock that would be taxed at up to 37% as ordinary income inside an IRA can instead be taxed at 15% or 20% as long-term capital gains. That spread is the NUA tax benefit.

The IRA rollover tax trap

When a 401(k) recordkeeper receives a rollover request at retirement, the default process rolls all assets — including employer stock — into a traditional IRA. This is straightforward to execute and defers all tax until you withdraw the money. It feels like a tax savings.

The long-term cost is significant: once employer stock is inside a traditional IRA, the NUA election is permanently gone. There is no way to retroactively un-roll the stock. Every dollar that eventually comes out of the IRA — including all of the appreciation that built up over decades — is ordinary income.

There are three additional tax costs of the IRA rollover for appreciated employer stock:

1. Required Minimum Distributions (RMDs). All traditional IRA balances are subject to RMDs starting at age 73 (or 75 if born in 1960 or later, per SECURE 2.0 § 107). You cannot choose to take out only capital gains — RMDs are all ordinary income at your marginal rate.
2. No step-up at death. Assets in a traditional IRA pass to heirs as IRD (income in respect of a decedent), with no step-up in basis. Heirs pay ordinary income tax on every withdrawal.
3. Bracket stacking. Large IRA balances force large RMDs in later retirement, which stack on top of Social Security and pension income and push marginal rates higher. This compounds the tax cost of rolling high-appreciation stock into an IRA.

The NUA solution: converting ordinary income to capital gains

The NUA election, executed correctly, moves employer stock out of the pre-tax 401(k) system and into your taxable brokerage account — where the appreciation becomes long-term capital gain territory.

The mechanics require four conditions to be met (IRC § 402(e)(4)):

1. Qualifying event. You've had a separation from service, reached age 59½, died, or become disabled.
2. Lump-sum distribution. You must distribute the entire vested balance from the plan in a single tax year. You can roll cash and fund assets into an IRA and take the employer stock in-kind — but the distribution of non-stock assets must happen in the same calendar year.
3. Employer stock only. Only actual shares of employer stock in the 401(k) qualify. Cash, mutual funds, and other plan assets do not.
4. Plan support. The plan must allow in-kind stock distributions. Most large plans do; verify before relying on NUA.

If all four conditions are met, you request an in-kind transfer of the employer shares to a taxable brokerage account. The plan issues a 1099-R with the cost basis in Box 2a (the taxable distribution amount) and the NUA appreciation in Box 6 (excluded from ordinary income). You report Box 2a as ordinary income on your return in the distribution year. When you later sell the shares, the NUA amount (Box 6) is automatically long-term capital gain — even if you sell the day after distribution.

2026 rate comparison: ordinary income vs. capital gains

The tax benefit of NUA comes from the spread between ordinary income rates and long-term capital gains (LTCG) rates. In 2026, that spread is significant:

The gap between "IRA rollover at 37% ordinary income" and "NUA appreciation at 15–23.8% LTCG" is the core tax savings of the NUA election. For a $900,000 appreciation position:

• IRA rollover (withdrawn over time at 37%): $333,000 in federal tax
• NUA election (sold at 15%): $135,000 in federal tax
• NUA election (sold at 23.8%): $214,200 in federal tax (high-income filer)

Even at the worst-case NUA rate (23.8%), you save $118,800 in federal tax compared to the IRA rollover at 37%. At 15%, you save $198,000.

Worked example: $1M employer stock, $100K cost basis

Robert is 63, married filing jointly, planning to retire this year. He has $1M in company stock inside his 401(k) with a $100K cost basis (10:1 appreciation ratio). He also has $600K in mutual funds in the same plan. His pension will provide $90K/year in retirement income.

Option A: Roll everything to an IRA (default)

Robert rolls the full $1.6M to a traditional IRA. No immediate tax due. The $1M in company stock becomes an undifferentiated IRA asset and will eventually come out as ordinary income — either voluntarily or via RMDs starting at age 73.

Assuming the stock portion grows modestly to $1.3M by age 73 and is withdrawn over 20 years at an average 28% effective federal rate (blended across his pension income + RMDs):

• Federal tax on $1.3M employer stock portion: ~$364,000
• No estate step-up — heirs inherit the tax burden

Option B: NUA election on employer stock, roll funds to IRA

Robert distributes the $1M in employer shares in-kind to a taxable brokerage account. He rolls the $600K in mutual funds to an IRA in the same tax year (satisfying the lump-sum distribution requirement).

Distribution year tax (ordinary income on $100K cost basis):

• Pension $90K + NUA cost basis $100K = $190K total ordinary income
• MFJ standard deduction $33,100 → taxable income ~$157K
• Marginal rate on the $100K: 22–24%
• Approximate federal tax on basis: ~$23,000

Tax on NUA appreciation ($900K) when sold:

• Sold in tranches over 6–8 years alongside pension income, staying mostly in the 15% LTCG bracket
• At 15% LTCG on $900K: $135,000
• If some sold at 20%+NIIT due to IRMAA-year avoidance: ~$158,000

Total NUA tax cost: $23,000 + $135,000 = ~$158,000

Federal tax savings vs. IRA rollover: ~$206,000

Additionally, the $1M stock is no longer inside the pre-tax IRA, reducing future RMDs by roughly $50K/year. That means lower IRMAA exposure, lower Social Security taxation, and more control over when and how much tax Robert pays each year.

Tax minimization strategies beyond the NUA election itself

The NUA election reduces the headline tax rate on appreciation. Several additional strategies can further reduce what you owe:

Tranche selling to manage LTCG brackets

You don't have to sell all NUA stock immediately. By selling in tranches over multiple years, you can keep your annual capital gains income below the 20% threshold (or even the 0% threshold in low-income early-retirement years before RMDs start). This is the most common post-NUA tax strategy.

Charitable gifting of appreciated shares

Donating NUA stock directly to a donor-advised fund (DAF) or qualified charity avoids capital gains entirely. You get a fair market value deduction (subject to AGI limits) and pay zero LTCG tax on the appreciation. For retirees with philanthropic intent, this eliminates a large portion of the NUA tax bill. A charitable remainder trust (CRT) can also provide an income stream while deferring the capital gains even further.

0% capital gains harvesting before RMDs begin

The pre-RMD window — typically ages 60–72 — is when many retirees have relatively low taxable income. If your pension and Social Security keep you below the 0% LTCG threshold ($98,900 MFJ in 2026), you can sell NUA stock tax-free in those years. This requires careful planning around Social Security provisional income, but the opportunity is significant. See: NUA and the 0% capital gains bracket.

Estate step-up planning

If you hold NUA stock until death, the appreciation since distribution date gets a full step-up in basis under § 1014. Heirs inherit the stock at market value and owe zero capital gains on appreciation that occurred during your lifetime. The cost basis portion distributed in the year of NUA is IRD (no step-up on that), but the subsequent appreciation is fully stepped up. This makes the NUA hold-to-death strategy highly tax-efficient for estate planning. See: NUA and estate planning.

IRMAA timing

Medicare Part B and Part D premiums are based on MAGI two years prior (the "IRMAA lookback"). Large NUA distributions — and large NUA stock sales — spike MAGI and can trigger IRMAA surcharges. Planning the distribution year before age 63, and spreading post-NUA sales across years, minimizes Medicare premium exposure. See: NUA and IRMAA.

Who benefits most from the NUA election

The tax benefit of NUA grows with the appreciation ratio. Here's how the federal savings scale:

Employees most likely to benefit:

• Long-tenure employees at a single employer — decades of employer matching in company stock typically produces very low average cost basis.
• ESOP participants — employer contributions to ESOPs are often at very low or zero cost to employees, producing extreme appreciation ratios.
• Employees at stable, long-performing public companies — industrials, financials, energy, and consumer staples sectors where 401(k)s have held company stock for 20+ years.
• Retirees with moderate post-retirement income — the LTCG rate benefit is largest when your future ordinary income bracket would have been 32–37%.
• Those with estate planning goals — the step-up at death can eliminate capital gains entirely on held NUA stock.

When NUA doesn't minimize taxes

NUA is powerful, but it is not always the optimal strategy. It doesn't help — and can hurt — in these situations:

• Low appreciation ratio (under 2:1). When the cost basis is close to market value, the LTCG spread saves little, but the distribution-year ordinary income hit on the basis is real. The calculator often shows IRA rollover winning in this case.
• California, New York, New Jersey, Oregon residents. These states tax capital gains as ordinary income at rates of 9–13%. NUA still saves federal tax, but the state benefit is zero or minimal. The breakeven appreciation ratio shifts significantly. See: NUA and state taxes.
• Very short retirement horizon. Time value of money matters. Paying tax on the basis today vs. deferring everything to later years requires a present-value analysis. Short horizons and low discount rates can favor deferral.
• Plans that don't permit in-kind distribution. Some 401(k) plans — particularly closely held ESOP plans — don't allow distribution of stock in-kind. If the plan requires cash-only distribution, NUA is unavailable regardless of the math.
• Under-55 with no penalty exemption. The 10% early withdrawal penalty applies to the cost basis portion if you're under 55 (or 59½ for in-service distributions). This erodes but usually doesn't eliminate the advantage for high-ratio positions. See: NUA before age 55.

Next steps

If you have significant appreciated employer stock in a 401(k), the most important action is to model the numbers before any distribution decision. Once you roll employer stock into an IRA, the NUA election is gone permanently.

For a step-by-step eligibility walkthrough, try the NUA Eligibility Checker. For a deeper breakdown of how NUA is taxed at the federal level, see How NUA Is Taxed: The Three-Layer Tax Structure. For the full decision framework, see When NUA Wins vs. Loses.

The analysis is complex enough that most employees benefit from working with an advisor who specifically models NUA before making any rollover recommendation. See: How to Find a Fee-Only NUA Advisor.

1. IRS Rev. Proc. 2025-32 — 2026 capital gains tax thresholds: 0% bracket up to $49,450 (single) / $98,900 (MFJ); 15% bracket to $550,000 (single) / $618,150 (MFJ); 20% above those thresholds. IRS.gov Rev. Proc. 2025-32
2. IRC § 402(e)(4) — Net Unrealized Appreciation rules and qualifying distribution requirements. law.cornell.edu/uscode/text/26/402
3. IRS Publication 575 — Pension and Annuity Income: NUA treatment, 1099-R Box 6 reporting, and LTCG classification rules. IRS.gov/publications/p575
4. SECURE 2.0 Act of 2022 (§ 107) — RMD age 73 for those born 1951–1959; age 75 for those born 1960 or later. IRS.gov retirement-topics-RMDs
5. IRC § 1014(c) — IRD exception to step-up in basis: NUA cost basis distributed during lifetime is IRD; post-distribution appreciation is eligible for step-up. law.cornell.edu/uscode/text/26/1014

Tax values verified as of May 2026. Dollar thresholds based on IRS Rev. Proc. 2025-32.