A 62-year-old engineer retiring next spring has $1.4 million in her 401(k). Roughly $400,000 sits in her employer’s stock, purchased over two decades through payroll deferrals and matching contributions at a blended cost basis near $60,000. Her advisor’s first instinct is a clean rollover into an IRA. That single move would cost her tens of thousands of dollars she does not have to pay.
The rule she needs to know is Net Unrealized Appreciation, or NUA. It lives in IRC Section 402(e)(4) and applies only to employer securities held inside a qualified plan. If her employer stock stays inside the 401(k) until rollover, every future dollar of gain becomes ordinary income when withdrawn. If she uses NUA instead, the appreciation is taxed at long-term capital gains rates for the rest of her life.
How the NUA Election Works
Four conditions must align. First, a triggering event: separation from service, reaching age 59½, disability, or death. Second, a lump-sum distribution of the entire 401(k) balance in a single tax year. Third, the employer shares must move in-kind to a taxable brokerage account rather than an IRA. Fourth, cash and non-employer-stock assets can roll to an IRA in the same year.
When the shares land in the taxable account, only the cost basis is taxed as ordinary income that year. The appreciation, the NUA, is not taxed until she sells the shares, and when she does, it is taxed at long-term capital gains rates regardless of how long she has held the shares outside the plan. Any additional appreciation after the distribution date follows normal short- or long-term rules.
Running the Math on Company Stock
Assume the shares are worth $400,000 with a $60,000 basis. Their other retirement income lands them in the 24% bracket, which in 2026 covers taxable income above $211,400, and their combined taxable income puts long-term gains squarely in the 15% capital-gains bracket that runs from $98,901 to $613,700 for joint filers in 2026.
Under the NUA election, she owes ordinary income tax on the $60,000 basis (roughly $14,400 at 24%) in the distribution year. If she then sells the entire block, the $340,000 of NUA is taxed at 15%, another $51,000. Total federal tax: about $65,400.
Roll the same shares into an IRA and the arithmetic flips. Every future withdrawal, basis and appreciation alike, is ordinary income. Liquidating the full balance through the IRA at ordinary rates costs substantially more, and the bill climbs higher once RMDs, Social Security, and pension income stack up. The NUA election can save this household tens of thousands of dollars, and that ignores the follow-on damage from IRMAA and Social Security taxation.
The Cascade Most Retirees Miss
Ordinary-income withdrawals from a traditional IRA feed directly into the formulas that make up to 85% of Social Security taxable and trigger Medicare IRMAA surcharges on a two-year lookback. Long-term capital gains from NUA shares still count toward MAGI, but they are taxed at a lower headline rate. Careful sequencing (selling shares in years when other income is low) can keep gains inside the 0% or 15% capital-gains brackets. The IRA rollover route offers no such lever.
One caution: concentrating a large position in a single employer’s stock is a risk in itself. NUA is a tax strategy on its own; the concentration risk still needs its own solution. Diversifying after the distribution simply means paying the capital-gains tax as shares are sold, which is exactly what the election was designed to enable.
Three Actions Before You Sign the Rollover Paperwork
- Pull your cost basis statement from the plan administrator. Ask for the average cost basis of employer shares and, if available, lot-level basis. NUA only makes sense when appreciation is large relative to basis. A common rule of thumb: basis under 30% of market value is where the math starts to favor the election.
- Model both paths in the same spreadsheet. Compare the NUA election against a full IRA rollover across a 10-year horizon, including projected RMDs starting at 75, Social Security taxation, and IRMAA brackets. The break-even is rarely close once IRMAA is included.
- Do not initiate any distribution before confirming lump-sum eligibility. Taking a partial distribution in a prior year, or missing the single-tax-year requirement, permanently disqualifies the NUA treatment on that stock. A fee-only CPA or CFP who has processed NUA transactions is worth the engagement fee here.
The average Baby Boomer 401(k) balance sits at $267,900, but readers with seven-figure plans and long tenures at a single public employer are exactly the population NUA was written for. The election is one-shot and irreversible. Get it right before the paperwork gets processed.
Contact [email protected] for any questions or corrections.
Top Gaining Stocks
Top Losing Stocks