Deciding what to do with employer stock in a 401(k) when you leave a job is one of the more complex — and potentially rewarding — retirement decisions you’ll face. Net Unrealized Appreciation (NUA) treatment can convert long-term growth inside a tax-deferred 401(k) into long‑term capital gains treatment when you sell shares, often delivering meaningful tax savings versus rolling everything into an IRA. But NUA has strict rules and knock‑on effects for required minimum distributions, Roth strategies, pensions and Social Security timing.

What this guide covers

  • What NUA is and when it applies
  • Step-by-step decision process when leaving an employer
  • Concrete tax math examples
  • How NUA interacts with IRA rollovers, Roth planning, RMDs, pensions and Social Security
  • Practical checklist and timing considerations for 2026

Quick definition: What is NUA?

NUA stands for Net Unrealized Appreciation. It is the difference between the market value of employer-stock held inside a qualified retirement plan (like a 401(k)) and the cost basis (what the company paid for those shares, or the amount you contributed for them). If you take a qualifying lump‑sum distribution of your employer plan when you separate from service, you can move the employer stock to a taxable brokerage account and pay ordinary income tax only on the stock’s cost basis in the year of distribution. The appreciation (NUA) is taxed later at long‑term capital gain rates when you sell the shares. That split—ordinary income on basis now, capital gains on appreciation later—can be a large tax advantage.

Key eligibility rules (must-check items)

  • NUA only applies to employer stock distributed from an employer plan — not to mutual funds or non‑employer securities.
  • Generally requires a lump‑sum distribution of the entire plan balance within the same tax year you separate from service (or after death). Partial rollovers that include employer stock into an IRA will typically forfeit NUA treatment.
  • If you roll employer stock into an IRA, the special NUA tax treatment is lost forever.
  • Documentation of cost basis in plan records is crucial — ask your plan administrator for the basis statement before distribution.

A six-step decision process when you leave an employer

  1. Inventory the plan and confirm employer stock details.

    Request an account statement showing the quantity of company shares, the plan‑recorded cost basis, and the total plan balance. Confirm whether some shares are restricted or subject to company repurchase rights.

  2. Confirm you qualify for a lump‑sum distribution.

    Ask the plan administrator whether you can take a lump‑sum distribution (the entire plan balance) in the year you separate. If the plan requires you to roll over certain components or disallows immediate lump sum, you may lose NUA eligibility.

  3. Run tax scenarios: rollover vs. NUA vs. partial strategies.

    Compare outcomes for:

    • Rolling the entire 401(k) (including company stock) into an IRA.
    • Taking a lump‑sum distribution, using NUA for company stock and moving the rest to an IRA.
    • Taking a lump‑sum distribution and selling stock immediately (pay ordinary income on basis + capital gains on NUA realized at sale).

    Project taxes across likely marginal tax rates and long‑term capital gains rates you expect over time. If your marginal ordinary rate at distribution would be high, consider whether spreading ordinary income or timing the distribution makes sense.

  4. Assess RMD and IRA implications.

    Once you remove employer stock from the plan into a taxable account, that portion is no longer subject to RMDs from the employer plan. However, any pre‑tax rollover funds you moved to an IRA will remain subject to required minimum distributions when you reach the applicable RMD age (as of 2026, age 73 for most taxpayers under SECURE 2.0). Selling NUA shares later converts the appreciation into capital gains, not IRA‑taxed ordinary income.

  5. Coordinate with Roth and pension decisions.

    NUA and Roth conversions are separate pathways. Rolling employer stock into an IRA forfeits NUA but may make Roth conversions simpler if you want to convert pre‑tax assets over time. If you keep stock as NUA in a taxable account, you cannot “convert” that appreciation to a Roth without creating a taxable event equal to the built‑in gain. Consider whether future Roth conversions are part of your long-term tax strategy.

  6. Decide, document, and execute with professional help as needed.

    Make the election in writing, get the plan’s cost basis confirmation, and ensure transfers are executed correctly — typically moving company stock to a taxable brokerage account while rolling other plan assets to an IRA to preserve their tax shelter. Work with a CPA or financial planner for tax timing and to avoid inadvertent rollover that kills NUA.

A concrete example

Sample numbers make the difference clear. Imagine the following at separation:

  • 401(k) total balance: $500,000
  • Employer stock portion: Market value $300,000; cost basis $60,000 (NUA = $240,000)
  • Remaining plan investments: $200,000
  • You are in the 24% marginal ordinary tax bracket; long‑term capital gains rate is 15%

Option A — Roll entire balance into an IRA:

  • No immediate tax; later, RMDs will be taxed as ordinary income at your then‑current rate.
  • When you sell the company stock inside the IRA, the appreciation is taxed as ordinary income — likely higher than capital gains.

Option B — Lump sum with NUA:

  • Tax owed in year one = ordinary income on cost basis: $60,000 × 24% = $14,400.
  • The $240,000 of appreciation is not taxed until you sell the shares and then taxed as long‑term capital gain: $240,000 × 15% = $36,000 (only when sold).
  • Total eventual tax on the stock = $14,400 + $36,000 = $50,400, compared with paying ordinary rates on $300,000 if rolled into an IRA and later withdrawn (which would be $300,000 × 24% = $72,000, assuming same rate).

In this example, NUA yields a material tax savings — but note the time value of tax payments, possible changes in tax rates, and the fact that you pay ordinary tax earlier on the basis. Run scenarios with your expected future marginal rates and capital gains rates before deciding.

How NUA interacts with pensions and Social Security

Pensions and Social Security benefits factor into your broader tax picture:

  • If a defined‑benefit pension or Social Security makes you subject to higher marginal tax brackets in the year you plan an NUA distribution, that could reduce the benefit of NUA by raising the ordinary tax on the cost basis.
  • Conversely, if you can time a lump‑sum NUA distribution in a year with low taxable income (e.g., early retirement before claiming Social Security or receiving pension payments), you may realize the most benefit.
  • Consider interaction with provisional income rules that can make portions of Social Security taxable — a large ordinary income event can push more Social Security into taxable status.

Pitfalls, watchpoints and planning tips

  • Document basis before distribution: Plan records must show the employer stock cost basis. If the plan administrator lacks basis records, you may face higher taxes.
  • Avoid accidental rollovers: Rolling employer stock into an IRA negates NUA. Ensure the transfer instructions move the company stock to a taxable brokerage account and the remainder to an IRA if you intend NUA.
  • Spousal or plan consent: Some plans require spousal consent or have plan‑specific rules — confirm early.
  • Company repurchase or restriction: If your employer retains repurchase rights or restrictions, NUA may be complicated or infeasible until restrictions lapse.
  • Estate planning: NUA shares held in a taxable account get a step‑up in basis at death, potentially eliminating the built‑in gain tax for beneficiaries — a notable estate planning consideration.
  • Timing matters: Coordinating NUA with pension start dates, Social Security claiming, and anticipated RMDs can materially change lifetime taxes. Use a tax pro.

When NUA is usually NOT the right answer

  • Your company stock has minimal appreciation (little NUA).
  • You expect to be in a much lower ordinary tax bracket later and prefer to defer and then convert to Roth gradually.
  • Plan rules make a lump‑sum distribution impossible or heavily restricted.
  • You need liquidity or diversification immediately and can’t tolerate holding concentrated company stock in a taxable account.

Practical checklist before you act

  1. Request a current statement showing company stock market value and plan basis record.
  2. Ask your plan administrator if a lump‑sum distribution in the year of separation is allowed and how they handle employer stock transfers.
  3. Run tax scenarios (ordinary vs. capital gains; impact on Social Security taxation and Medicare IRMAA if relevant).
  4. Confirm brokerage account setup for receiving employer stock and an IRA for rolling other assets.
  5. Get written instructions and spousal consent forms if needed; don’t rely on verbal directions.
  6. Execute the distribution early in the calendar year, if possible, to allow time for tax planning and potential Roth conversions in the same year.
  7. Engage a CPA or fiduciary advisor to confirm tax calculations and document the decision.

Final words: NUA can be powerful — but it’s context‑sensitive

NUA is a high-value tool for converting appreciated employer stock into capital-gain treatment, potentially saving tens of thousands of dollars in taxes for the right taxpayer. But it is rule‑heavy and irrevocable once you roll the stock into an IRA. The decision sits at the intersection of 401(k) mechanics, IRA and Roth planning, required minimum distribution timing, defined‑benefit pension timing and Social Security strategy.

If you hold significant employer stock in a 401(k) and are considering leaving the company, treat NUA as a core planning item. Gather the documentation, run concrete tax scenarios, and consult a tax professional to align the NUA decision with your overall retirement plan.