Net Unrealized Appreciation (NUA) in a 401(k)

The net unrealized appreciation (NUA) strategy is a tax-deferral tactic available when you leave your job with employer stock in your 401(k). Instead of rolling the stock to an IRA (which taxes any appreciation as ordinary income), you take the stock as a lump-sum distribution and defer the tax on the appreciation until you sell the shares. The appreciation is then taxed at long-term capital gains rates—often significantly lower than ordinary income rates.

How NUA works

When you leave your employer, your 401(k) balance can usually be rolled to a traditional IRA. A rollover defers taxes, but it also means any company stock inside is treated as ordinary income when eventually withdrawn—losing the tax advantage of capital gains rates.

The NUA exception allows you to distribute the employer stock directly (not rolled to an IRA) and pay ordinary income tax on only the cost basis (the original price the plan paid for it). The unrealized appreciation—the gain since purchase—is taxed at capital gains rates when you sell the shares, not when you receive them.

Example: your 401(k) holds 500 shares of your former employer stock. The plan originally bought them at $40/share (cost basis = $20,000). Today, the stock is $100/share (current value = $50,000). The unrealized appreciation is $30,000.

Under NUA:

• You take the stock out as a distribution.
• You pay ordinary income tax on $20,000 (the cost basis).
• You hold the shares in a taxable account.
• When you sell later, you pay long-term capital gains tax on the $30,000 appreciation.

If the stock is worth $100/share when you sell, you pay capital gains tax on the gain from $40 to $100. If it drops to $60/share before you sell, you pay capital gains tax on $20/share ($10,000 total gain), even though you originally received it at $100/share.

The lump-sum requirement

To use NUA, you must take a lump-sum distribution of your entire 401(k) balance in a single calendar year. You cannot cherry-pick only the company stock and leave other assets rolling to an IRA. This is a hard rule: the election to use NUA applies to the entire distribution.

In practice, this means:

1. Distributing all employer stock at NUA treatment.
2. Rolling other 401(k) assets (cash, mutual funds, bonds) to an IRA.
3. Holding the company stock in a taxable brokerage account.

If you do not meet the lump-sum requirement—say, you roll the stock to an IRA instead—you lose the NUA benefit forever. The appreciation is then taxed as ordinary income when withdrawn from the IRA.

Cost basis vs. current value taxation

The ordinary income tax is owed only on cost basis, not on current value. If the stock has appreciated since the plan bought it, this is the critical advantage.

Using the prior example:

• Cost basis: $20,000
• Current value: $50,000
• Ordinary income tax at 37% (top bracket): $7,400
• Later, you sell at $100/share.
• Capital gains tax on $30,000 appreciation at 20% (long-term rate): $6,000
• Total tax: $13,400

By comparison, if you rolled it to an IRA:

• Entire $50,000 is ordinary income when eventually withdrawn.
• Tax at 37%: $18,500

The NUA strategy saves $5,100 in this example. With large positions or high appreciation, the savings are substantial.

Holding period for capital gains treatment

A common misconception: you must hold the stock for more than one year after the distribution to qualify for long-term capital gains treatment. This is not how NUA works. The capital gains rate applies to the unrealized appreciation regardless of how long you hold after distribution—even if you sell the next day.

What matters is that the appreciation itself qualifies as long-term gain, which it does because the stock was held in the 401(k) for years before distribution. The holding period for NUA is not reset by distribution.

However, for tax reporting clarity, many advisors recommend holding for >1 year post-distribution to ensure no audit complications.

The ordinary-income hurdle

While NUA converts future gains to capital gains rates, you still owe ordinary income tax on the cost basis at distribution. For highly appreciated stock, this is a one-time bill that can be large.

If the stock costs $20,000 in basis and you are in the 37% bracket, you owe $7,400 immediately. You must either:

• Use cash outside the 401(k) to pay the tax.
• Ask the plan to withhold some of the distribution (though withholding is incomplete and may not cover full liability).

Some people do NUA only when they have planned for this tax bill—e.g., in a year of lower ordinary income (early retirement, sabbatical) or when they have other sources to cover it.

Who should consider NUA

NUA is most valuable when:

• The stock has appreciated significantly (unrealized gain » cost basis).
• Your tax bracket is high (the ordinary-income cost is steep, but the capital-gains savings later are worth it).
• You plan to hold the stock (if you sell immediately, the benefit is modest).
• The company is large-cap with stable dividends (smaller companies or highly volatile stock introduce concentration risk).

NUA is least valuable when:

• The stock is only modestly appreciated (the tax benefit is small).
• You plan to sell immediately (capital gains are owed soon anyway).
• You believe the stock will decline (you pay ordinary income on a position that falls in value).

Concentration risk

Taking company stock out of a 401(k) creates concentration risk. A large position in a single stock exposes you to company-specific volatility. If the employer faces legal trouble, competitive pressure, or accounting scandal, the entire position can crater. Diversification is generally prudent, but diversifying away from NUA stock triggers capital gains tax.

Many use NUA for the tax benefit while planning to diversify gradually—selling some shares each year and reinvesting in a diversified portfolio, spreading the capital gains tax across multiple tax years.

Claiming NUA

NUA is claimed on Form 4972 (Ordinary Gains from Lump-Sum Distributions). The plan administrator provides a cost basis statement (Box 5 on the Form 1099-R). You report the cost basis as ordinary income, and the unrealized appreciation flows to your taxable brokerage account without additional tax reporting until you sell.

The 401(k) plan must provide a cost-basis estimate in writing before distribution, or the opportunity may be lost.

Comparison with other strategies

NUA is unique in deferring tax on appreciation while in employment.

See also