This 401(k) Rollover Move Can Save a High Earner $50,000 in Taxes

A 58-year-old leaving a job with $1.2 million in a 401(k) faces a decision that looks routine but carries a $47,600 federal tax variable hiding in plain sight. If that 401(k) holds a significant block of appreciated company stock, the choice between rolling everything to a traditional IRA versus using the Net Unrealized Appreciation (NUA) strategy is one of the most consequential tax moves available before retirement begins.

The Split That Changes the Math

For those who are unfamiliar, NUA is a tax code provision that allows you to take a lump-sum distribution of employer stock from a 401(k) and pay ordinary income tax only on the original cost basis, not on the current market value. The appreciation above that basis gets taxed at long-term capital gains rates when you eventually sell the shares.

Consider a concrete example: $350,000 in company stock with a $70,000 cost basis. Two paths, very different outcomes, and it starts with Path one, which would have someone roll the stock into a traditional IRA along with everything else. Every dollar comes out as ordinary income later. For someone in the 37% tax bracket, that means $129,500 in federal tax on the $350,000 position when withdrawn.

Now, consider Path two: take the NUA distribution at the triggering event. Only the $70,000 basis is taxed as ordinary income at the time of distribution, generating $25,900 in federal tax. The remaining $280,000 in appreciation is taxed at the long-term capital gains rate when sold, which, for high earners, is 20%, resulting in $56,000 in tax on the NUA portion. Total federal tax: $81,900, compared to $129,500 under the IRA route. The tax savings on that $280,000 spread are approximately $47,600 at the federal level alone, easily clearing $50,000 when state taxes are factored in.

The Triggering Event Requirement

NUA requires a qualifying triggering event to apply. It requires a qualifying triggering event: separation from service, reaching age 59½, disability, or death. The distribution must be a lump-sum distribution of the entire account balance in the same tax year. Partial rollovers disqualify the strategy, which eliminates most casual attempts at NUA planning.

The two-year IRMAA lookback adds another layer, as the 2026 IRMAA surcharge threshold starts at $109,000 for single filers and $218,000 for married filing jointly. A lump-sum distribution that pushes MAGI above those levels in the distribution year triggers Medicare premium surcharges two years later. The 2026 IRMAA Part B surcharges range from $81.20 to $487.00 per month per person, with annual IRMAA surcharges per person ranging from $1,148 at Tier 1 to $6,936 at Tier 5 when Part B and Part D are combined. For a married couple, those amounts double.

The NUA strategy does not eliminate this exposure, but it reduces it relative to the IRA alternative. With a traditional IRA rollover, the same appreciated stock generates ordinary income every year it is withdrawn, potentially triggering IRMAA annually for decades. The NUA approach concentrates the ordinary income hit into one year (the basis), while capital gains recognition can be timed and spread across multiple years after distribution.

Who Does Math Favor?

NUA works best when three conditions align: the cost basis is low relative to current value (a ratio of $70,000 to $350,000, or 20%, is favorable), the account holder is in a high ordinary income bracket now and expects to remain there in retirement, and the stock has been held long enough that the NUA qualifies for long-term treatment. It works poorly when the cost basis is high relative to market value, because ordinary rates apply to the basis regardless, and the capital gains advantage shrinks.

The strategy also carries concentration risk. Taking a lump-sum stock distribution means holding a single-company position outside the 401(k). That position can be sold immediately after distribution to diversify, but the capital gains clock starts at distribution, not at original purchase.

Three Steps Worth Taking Now

1. Pulling the 401(k) plan statement and identifying the cost basis of the employer stock position is the starting point. Plan administrators are required to provide this. If the basis is below 30% of the current market value, the NUA calculation can be run against a full IRA rollover using the expected ordinary income bracket in retirement.
2. Whether a qualifying triggering event applies in the near term is a threshold question. Separation from service at age 55 or older also opens the Rule of 55 for penalty-free access, but sequencing matters: the NUA lump-sum distribution must be completed before taking any Rule of 55 withdrawals from the same plan, or the NUA election may be disqualified. Once the stock is distributed under NUA, the Rule of 55 may apply to other plan assets or to the taxable account in which the stock now resides.
3. If your combined income in the distribution year will exceed $109,000 single or $218,000 joint, model the two-year IRMAA impact. The standard 2026 Part B premium is $202.90 per month; a single IRMAA tier jump adds $81.20 per month on top of that, and the surcharge applies to both spouses independently. Tax planning for a single distribution year justifies engaging a fee-only advisor.