When Do I Owe the 23.8 Percent Capital Gains Tax Rate?

Executives owe the 23.8 percent federal capital gains tax rate when their taxable income crosses into the top 20 percent long-term capital gains bracket while their modified adjusted gross income exceeds the threshold for the 3.8 percent Net Investment Income Tax. Because ordinary wages stack beneath investment gains on a federal return, a high base salary and routine equity vestings can push a large stock sale into that top tier even when the investor holds the shares for years.

The 23.8 percent figure is not a standalone bracket listed in standard IRS rate tables. Instead, it reflects two separate federal levies operating at the same time on the same incremental dollars of investment gain. Under IRS rules, high-earning filers face a 20 percent maximum rate on long-term capital gains alongside a 3.8 percent surtax on net investment income, producing a combined top marginal rate of 23.8 percent on gains above both statutory thresholds.

For an executive preparing to sell a concentrated block of company stock, the practical decision involves liquidating the position in a single calendar year or spreading sales across multiple years. Liquidating all at once reduces single-company exposure immediately but can push substantial gains into the 23.8 percent tier. Spreading sales over time may preserve lower-bracket room, though leaving shares unsold exposes the portfolio to ongoing market and company-specific price risk.

When the 23.8 Percent Rate Applies

The 23.8 percent rate arises only when an individual meets two distinct IRS criteria in the same tax year. Under IRS Topic 409 on capital gains and losses, the maximum federal tax rate on net long-term capital gains is 20 percent for individuals with high taxable income. Separately, IRS guidance on the Net Investment Income Tax establishes an additional 3.8 percent surtax on certain investment income once modified adjusted gross income rises past a fixed statutory dollar threshold.

Because those two thresholds sit at different income levels, an executive rarely enters both taxes simultaneously on the exact same dollar of income. Many high earners trigger the 3.8 percent surtax long before their taxable income reaches the 20 percent capital gains bracket. During that intermediate zone, long-term stock gains face the 15 percent capital gains rate plus the 3.8 percent surtax, for a combined marginal rate of 18.8 percent before the top bracket takes effect.

The full 23.8 percent rate applies only to the slice of long-term capital gain that sits above both the Net Investment Income Tax threshold and the top capital gains threshold. Lower slices of income and gain continue to receive the lower marginal rates assigned to those brackets. Knowing where regular compensation ends and where capital gains begin allows an executive to estimate which portion of a proposed stock sale will stay at 18.8 percent and which portion will reach 23.8 percent.

How Long-Term Capital Gains Brackets Work

Federal tax law divides capital gains into short-term and long-term categories based on how long the seller held the shares. According to the IRS in Topic 409, a capital gain is considered long-term if the asset is held for more than one year before being sold. Gains on shares sold within one year or less are classified as short-term and taxed at ordinary marginal income rates, making the one-year holding mark a foundational dividing line for executives planning stock sales.

Long-term capital gains use three preferential federal brackets: 0 percent, 15 percent, and 20 percent, determined by total taxable income after deductions rather than by the size of the stock sale alone. For the 2025 tax year, the IRS specifies that the 20 percent capital gains rate applies to single filers with taxable income over $533,400. For married couples filing jointly in 2025, the 20 percent rate begins once taxable income exceeds $600,050.

Ordinary income sits at the base of the tax stack, and long-term capital gains sit on top of it. An executive does not receive a separate 0 percent or 15 percent capital gains allowance independent of salary, bonuses, and vested stock awards. If ordinary taxable income already consumes the 0 percent tier and most of the 15 percent tier, even a moderate long-term stock sale can spill over the $533,400 or $600,050 line and push the excess gain into the 20 percent bracket.

The Net Investment Income Tax (NIIT) Explained

The Net Investment Income Tax is a 3.8 percent federal surtax created to apply to investment earnings of higher-income households. Under IRS Topic 559, the NIIT applies to individuals whose modified adjusted gross income, known as MAGI, exceeds $200,000 for single filers or $250,000 for married couples filing jointly. Unlike the long-term capital gains brackets, these MAGI thresholds are fixed by statute and do not adjust upward each year for inflation, causing more executives to cross them over time.

IRS Topic 559 defines net investment income to include capital gains from selling securities, taxable dividends, and interest, along with certain rental and passive business income. For most corporate executives, the primary components are realized gains from stock sales and dividend distributions from vested shares or brokerage holdings. When MAGI crosses $200,000 for a single filer or $250,000 for a married couple filing jointly, that investment income becomes exposed to the 3.8 percent surtax regardless of whether the gain falls in the 15 percent or 20 percent bracket.

Reporting and calculating this surtax happens outside the standard capital gains worksheet. As outlined by the IRS, filers use Form 8960 to figure the amount of their Net Investment Income Tax and attach it to their annual federal return. Because MAGI starts from adjusted gross income before standard or itemized deductions, deductions such as mortgage interest or state taxes within statutory caps may lower taxable income for the 20 percent bracket without lowering MAGI below the NIIT line.

How RSU Vesting and Salary Push You Higher

Restricted stock units, or RSUs, are a common source of unexpected tax bracket compression for corporate leaders. According to IRS Publication 525, RSU vesting is generally treated as wages and included in gross income for the year in which the shares vest. That means the fair market value of vested shares appears directly on the executive's Form W-2 alongside base salary and annual cash bonuses, adding to ordinary taxable income even if the executive holds the shares rather than selling them immediately.

A frequent pitfall is forgetting that RSU vestings count as ordinary income and increase MAGI. An executive who views base salary alone as moderate may overlook scheduled quarterly or annual RSU vestings that steadily push total W-2 wages higher. Because every vested dollar increases both adjusted gross income and MAGI, a large vesting event can lift an executive past the $200,000 or $250,000 NIIT threshold and simultaneously consume a large share of the 15 percent capital gains bracket.

This stacking effect also creates timing interactions with employer tax withholding. Employers typically withhold federal income tax on vesting RSUs at supplemental flat rates that may lag behind an executive's actual marginal bracket, and employer withholding systems rarely account for the 3.8 percent NIIT on separate stock sales. When an executive sells previously vested long-term shares in the same year as large RSU vestings, the combined wage base leaves very little cushion before capital gains hit 20 percent plus 3.8 percent.

Calculating the Total Tax Hit: An Example

Consider Sarah, a single executive who earns $400,000 in W-2 salary and RSU vestings and holds a concentrated block of long-term company stock. Suppose Sarah wants to sell $200,000 of that long-term company stock. For this illustration, assume the entire $200,000 figure represents her long-term capital gain with negligible cost basis, and ignore deductions and tax credits so the interaction between ordinary wages and capital gains brackets remains clear.

Before Sarah sells a single share, her $400,000 in base W-2 salary and vested RSUs already places her well above the $200,000 MAGI threshold for single filers under the Net Investment Income Tax. As a result, every dollar of her $200,000 long-term capital gain will face the 3.8 percent surtax. At the same time, her $400,000 ordinary income fills the lower brackets and leaves only a limited amount of room inside the middle long-term capital gains bracket below the $533,400 single-filer threshold.

If Sarah sells the entire $200,000 stock block all at once in a single calendar year, her combined income exceeds $533,400. The slice of gain up to $533,400 is taxed at the middle long-term capital gains rate plus the 3.8 percent surtax. The remaining portion of the gain pushed above $533,400 enters the 20 percent capital gains bracket alongside the 3.8 percent surtax on that upper slice.

Alternatively, if Sarah divides the stock sale evenly across multiple calendar years while her $400,000 W-2 income and the statutory thresholds stay constant, each annual gain fits below the $533,400 ceiling. Under that multi-year schedule, her gains stay entirely below the 20 percent bracket, avoiding the top capital gains tier while still facing the 3.8 percent surtax. The trade-offs include the risk of the stock price falling during the second year, and questions to ask an advisor include her overall portfolio concentration and upcoming RSU vesting schedule.

Strategies for Managing the Tax Hit

When an executive holds a large position of appreciated company stock, timing the liquidation involves balancing tax bracket management against investment risk. IRS Publication 550 explains how to determine and report gains and losses on the disposition of investment property, including how cost basis and specific share-lot identification shape the taxable gain on any sale. Reviewing individual tax lots before placing an order helps clarify whether selling newer, higher-basis shares reduces the net capital gain even when gross proceeds are large.

Beyond lot selection, the central structural choice is whether to sell the entire stock block in a single tax year or divide the liquidation across two or more calendar years. Neither approach is inherently superior, because tax efficiency and market risk pull in opposite directions. A common pitfall is thinking that selling stock all at once is always the wrong move while ignoring the danger of a concentrated portfolio, where a steep drop in one company's share price can erase far more wealth than a higher tax bracket would cost.

The two timing approaches differ sharply in how they handle bracket exposure, reporting complexity, and ongoing market risk. Single-year liquidation prioritizes immediate diversification and price certainty over marginal rate minimization, whereas multi-year liquidation prioritizes keeping taxable income below the $533,400 single or $600,050 joint threshold while retaining exposure to the stock. Weighing these options depends on how much net worth is tied to the employer, the executive's cash-flow requirements, and whether future RSU vestings will add more shares.

• Selling the stock all at once involves liquidating the entire block of company stock in a single tax year. Pros include immediately diversifying the portfolio away from a single company, locking in the current stock price, and simplifying future tax reporting by handling the sale in one year. Cons include pushing more income into the 20 percent capital gains bracket, maximizing exposure to the 3.8 percent Net Investment Income Tax, and creating a larger single-year tax bill. People weigh this option when the executive is highly concentrated in company stock and prioritizes risk reduction over tax optimization.
• Spreading the sale over multiple years involves selling portions of the stock block across two or more tax years to manage taxable income. Pros include potentially keeping some capital gains in the 15 percent bracket, reducing the portion of gains subject to the highest tax rates, and spreading the tax liability over time. Cons include leaving the portfolio exposed to company stock risk for a longer period, requiring ongoing monitoring and execution of trades, and facing the possibility that the stock price drops before the remaining shares are sold. People weigh this option when the executive wants to minimize the total tax rate applied and is comfortable holding the stock longer.

Common Pitfalls to Avoid

One widespread misconception is assuming the 23.8 percent rate applies to all investment income on a return once a filer crosses an income threshold, rather than only the portion sitting above the statutory lines. Federal tax brackets and the Net Investment Income Tax operate marginally. Even when an executive's income pushes past $533,400 or $600,050, only the incremental gain above those thresholds triggers the 20 percent rate, while lower slices remain taxed at 0 percent or 15 percent.

A closely related error involves misapplying the formula for the 3.8 percent Net Investment Income Tax. According to IRS Questions and Answers on the Net Investment Income Tax, the NIIT is calculated on the lesser of net investment income or the amount by which MAGI exceeds the $200,000 single or $250,000 joint threshold. When a stock sale itself is what pushes MAGI just slightly over the threshold, only that small excess above $200,000 or $250,000 faces the 3.8 percent surtax, not the entire stock gain.

Executives also frequently confuse the 3.8 percent Net Investment Income Tax with the 0.9 percent Additional Medicare Tax on wages. Although both surtaxes share the same $200,000 single and $250,000 married filing jointly MAGI or wage thresholds, they apply to completely different income streams. The 0.9 percent Additional Medicare Tax applies strictly to earned wages, such as base salary and vested RSUs, and is often partially withheld by employers, whereas the 3.8 percent NIIT targets unearned investment income such as capital gains and dividends.

Finally, overlooking state capital gains taxes or assuming federal withholding on RSUs covers future stock sales can lead to estimated tax penalties. State tax regimes rarely mirror federal 0 percent, 15 percent, and 20 percent preferences, and many states treat long-term capital gains as ordinary income. Reviewing estimated tax rules and Form 8960 projections with a qualified tax professional before executing a large sale helps prevent cash-flow surprises when annual returns come due.

Key takeaways

• Ordinary W-2 salary and vested RSUs occupy the lower brackets before any capital gain is counted, leaving high-earning executives with narrow room below the $533,400 single or $600,050 joint threshold.
• The 3.8 percent NIIT begins at $200,000 of MAGI for single filers and $250,000 for married couples filing jointly—thresholds not indexed to inflation—so many executives enter the 18.8 percent combined zone well before reaching the 20 percent bracket.
• Crossing either threshold exposes only the incremental slice of gain or net investment income above the line to the higher rate, rather than repricing the entire return.
• Spreading stock sales across calendar years may reduce the share of gains taxed at 20 percent, yet holding an unhedged single-stock position exposes the executive to company-specific price declines during the waiting period.
• Reviewing Form 8960 mechanics alongside specific share-lot cost basis rules in IRS Publication 550 clarifies how much of a proposed liquidation represents taxable gain rather than return of basis.

Sources

• Questions and Answers on the Net Investment Income Tax (https://www.irs.gov/newsroom/questions-and-answers-on-the-net-investment-income-tax)
• Topic no. 559, Net investment income tax (https://www.irs.gov/taxtopics/tc559)
• Topic no. 409, Capital gains and losses (https://www.irs.gov/taxtopics/tc409)
• Publication 525 (https://www.irs.gov/publications/p525)
• About Form 8960, Net Investment Income Tax (https://www.irs.gov/forms-pubs/about-form-8960)
• About Publication 550, Investment Income and Expenses (https://www.irs.gov/forms-pubs/about-publication-550)