Don't Roll Over

Time and time again when my friends switch jobs, they add "rollover 401(k)" to the checklist without a second thought.

Financial advisors, parents, and the general internet have built up this mantra that leaving an employer means rolling over your 401(k). It's treated as hygiene, like forwarding your mail.

But that reflex can be incredibly expensive, especially if you worked at a public company whose stock did well.

The Mechanics

When you leave a job, your old 401(k) doesn't have to move. You really only have three options.

• Roll it into the new employer's 401(k). Move the balance into the plan at your next job.
• Roll it into an IRA. Move everything into an Individual Retirement Account you control.
• Do nothing. Many plans will simply let you keep the 401(k) right where it is.

The standard advice is option two: sweep the entire balance into one tidy IRA and never think about it again.

It stops being fine if your 401(k) holds shares of the company you worked for.

The Trap

Every dollar that eventually comes out of a 401(k) or an IRA is taxed as ordinary income, the same rate as your paycheck, climbing as high as 37% federal. That's the deal you made for the upfront tax break.

Many 401(k) plans let you buy shares of the very company sponsoring the plan. For company stock that has quietly multiplied inside the plan, that reflex is a disaster. Rolling that stock into an IRA takes a gain that could have been taxed at low capital-gains rates and reclassifies it as high-rate ordinary income, forever.

You end up volunteering for the highest possible tax on your single best-performing asset when the tax code has an explicit exception that lets you avoid it.

The Exception

The idea underneath it is simple once you split the stock into two pieces.

• Cost basis. What you originally paid for the shares.
• Net unrealized appreciation (NUA). Everything the shares gained on top of that basis while sitting inside the plan.

Normally those two pieces are taxed identically, both as ordinary income on the way out. NUA pries them apart.

Instead of rolling the shares into an IRA, you pull them out of the plan in-kind, the actual shares moved directly into a regular taxable brokerage account. When you do that, only the cost basis is taxed as ordinary income today. The appreciation that built up inside the plan is left alone until you sell, and that gain is taxed at long-term capital-gains rates, no matter how long you held the shares. Anything the stock gains after it leaves the plan is taxed under the normal holding-period rules.

That's the whole move. The small slice gets taxed like salary. The enormous slice rides out at the capital-gains rate. On a stock that has run, the gap between those two rates is where the money is.

NVIDIA

Say you joined NVIDIA in 2021 and started steering your 401(k) contributions and your employer match into company stock. Split-adjusted, the shares were trading around $19.50.

Five years later they're north of $200, more than a tenfold run. Suppose you accumulated 5,000 shares along the way, at an average cost of about $30. That's a $150,000 cost basis sitting on $1,050,000 of stock.

The appreciation, the part NUA protects, is $900,000.

Now you leave, and you reach the fork. Roll the whole thing into an IRA like the checklist says, or take the NVIDIA shares out under NUA. Assume an ordinary rate of 35% and a long-term capital-gains rate of 20%.

Same shares. Same company. Same $900,000 gain. The only difference is which box you checked on the way out.

The Catch

Like anything this good, NUA has rules, and getting one wrong collapses the whole election into a fully taxable mess. There are three.

• A triggering event. You have to leave the company, turn 59½, become disabled, or pass away. No event, no NUA.
• A lump-sum distribution. The entire 401(k) balance has to leave the plan within a single calendar year. The company stock goes in-kind to your brokerage account; the index funds and cash can roll into an IRA in the same move, but nothing can stay behind past December 31st.
• An in-kind transfer. The shares themselves have to move to a taxable account. If the plan sells them and hands you cash, or the stock lands in an IRA along with everything else, the election is gone for good.

The Long Game

NUA only works on company stock held inside the 401(k). For most people at a public company, that's not where the stock is.

Company stock usually piles up somewhere else. RSUs vest into a brokerage account, and an ESPP buys discounted shares that land there too. That exposure sits outside the plan, where NUA can never reach it.

The shares that earn the treatment are the ones bought inside the plan. If your 401(k) lets you hold company shares, steering some contributions into them is what plants the low-basis position NUA rewards years later. You can't transfer RSUs or ESPP shares in, since the plan runs on payroll cash, so it's a choice about your investment elections.

If you're going to hold company stock anyway, the place to hold it is inside the 401(k). That one choice is what can turn ordinary income into long-term capital gains years later.

When To Roll Over

NUA is a calculation, and sometimes the calculation says roll it over.

The math turns on the ratio of basis to value. NUA shines when the basis is tiny relative to the stock, like the NVIDIA case, where basis is barely 14% of the position. Flip that around: if you bought the stock recently and it's barely up, you'd be paying ordinary income tax today on almost the whole thing, for a sliver of capital-gains benefit later. Just roll it over.

The same goes if you plan to drain the account slowly in retirement at low brackets, or you simply don't want a concentrated single-stock bet sitting in a taxable account. The ordinary rate you're so afraid of might never actually arrive.

The point isn't that NUA always wins. It's that the default never even runs the numbers.

The Move

The reflex is to sweep everything into one neat IRA and stop thinking about it. For most 401(k) accounts that works. But the most valuable position in the account might be the one asset you should carry out by hand.

Look before you roll.