Has Company Stock in Your 401(k) Soared in Value? This Little-Known IRS Rule Could Slash Your Tax Bill

# Company Stock in Your 401(k)? A Tax Rule Most People Miss

If your company stock inside your 401(k) has climbed significantly in value, the IRS offers a lesser-known strategy that could cut your tax bill by thousands. It involves net unrealized appreciation (NUA), and most workers never learn about it until after they've already made costly mistakes.

Here's how it works. When you leave a job or retire and need to withdraw your 401(k), the IRS normally taxes the entire withdrawal as ordinary income. That means if you have $500,000 in your 401(k) and $200,000 of it is company stock that has appreciated substantially, you'd pay ordinary income tax on the full $500,000.

Net unrealized appreciation changes this calculation. NUA measures the gap between what your company shares cost when they entered your 401(k) and what they're worth today. The IRS allows you to separate company stock from the rest of your 401(k) and handle the tax treatment differently.

The strategy works like this. You take a lump-sum distribution of your entire 401(k). The company shares get transferred to a taxable brokerage account. You only pay ordinary income tax on the original cost basis of those shares, not the full current value. When you later sell the shares in the brokerage account, the appreciation gets taxed as long-term capital gains, which carry lower tax rates than ordinary income. Capital gains rates currently sit at 15% or 20% for most high earners, compared to ordinary income rates as high as 37%.

The math can be striking. Suppose you have company stock with a $100,000 cost basis that's now worth $400,000. Using NUA, you'd pay ordinary income tax on just $100,000. The $300,000 appreciation becomes taxable only when you sell, and only at capital gains rates. Without NUA, you'd pay ordinary income tax on the full $400,000.

This strategy works best when you own a substantial amount of company stock in your 401(k), the stock has appreciated significantly, and you plan to hold it long-term after leaving your employer. It also requires careful timing and coordination with your retirement plan administrator.

Several rules box in the NUA strategy. You must take the entire account balance as a lump sum in one calendar year. You cannot roll the company shares into an IRA, since that triggers ordinary income tax treatment. The shares must remain in a regular taxable brokerage account.

Not every retiree qualifies. The strategy makes sense primarily when company stock represents a substantial portion of your account and gains run high. If your company stock comprises only 10% of your 401(k), the benefit shrinks considerably.

Employees at major corporations with long tenure often benefit most. Workers at companies like Johnson & Johnson, Microsoft, or Apple who held company stock in their 401(k) accounts for decades may have enormous unrealized gains. A conversation with a tax professional or financial advisor before your departure can identify whether NUA applies to your situation.

The clock starts ticking the moment you separate from service. Your plan administrator will send distribution paperwork. Getting professional guidance early prevents mistakes that cost thousands in unnecessary taxes.