Why the 2026 Capital Gains Tax Brackets Compress Your Gains

What the 2026 Capital Gains Tax Brackets Actually Mean for Your Portfolio

The 2026 capital gains tax brackets are not a distant policy abstraction. For anyone holding $5M+ in appreciated assets, the TCJA sunset creates a concrete, time-sensitive planning window. The core issue is not that capital gains rates themselves change dramatically, but that the ordinary income bracket thresholds that determine which rate applies will compress, pushing more of your gains into higher tiers.

Here is what you need to understand before year-end 2025.

What the TCJA Sunset Actually Changes (and What It Does Not)

The Tax Cuts and Jobs Act of 2017 contains individual income tax provisions set to expire after December 31, 2025. The Tax Foundation has documented this extensively. Unless Congress acts, the tax code reverts to its pre-2018 structure on January 1, 2026.

The common misconception is that the long-term capital gains rates themselves (0%, 15%, 20%) are TCJA creations. They are not. Those rates are established under IRC Section 1(h) and remain intact. What the TCJA did was set the ordinary income bracket thresholds that determine which capital gains rate applies. When those thresholds compress post-sunset, more income falls into the 20% tier.

The top ordinary income rate reverts from 37% to 39.6%. For a married couple with substantial investment income, that shift in bracket boundaries can push a meaningful portion of long-term gains from the 15% rate to the 20% rate, adding tens of thousands in tax liability with no change to the headline capital gains rates at all.

The Congressional Budget Office projects that allowing TCJA individual provisions to expire as scheduled would increase federal revenues by approximately $4.6 trillion over the 2025 to 2034 window, with the largest impacts on higher-income households.

2025 vs. Projected 2026 Long-Term Capital Gains Tax Brackets

Per IRS Revenue Procedure 2024-40, the 2025 federal long-term capital gains brackets are:

Post-TCJA sunset, the bracket thresholds revert to pre-2018 levels adjusted for inflation. The exact 2026 numbers depend on final inflation adjustments and any legislative action, but the directional shift is clear: the 20% threshold drops, and the 15% band narrows. A married couple currently sitting just below the 20% threshold could find a significant portion of their gains crossing into the top tier.

Add the 3.8% net investment income tax (NIIT) under IRC Section 1411, which applies above $200,000 (single) and $250,000 (married filing jointly), and the true top federal rate on long-term gains is already 23.8%, not 20%. Those NIIT thresholds have never been inflation-adjusted since enactment in 2013, meaning they capture a far broader population today than Congress originally intended.

The effective top federal rate does not change dramatically at the headline level. The damage is in the bracket compression.

Total Tax Burden by State: Where You Live Matters as Much as What You Earn

Federal rates are only half the picture. For FATFIRE investors, state capital gains taxes can be the deciding variable in whether a transaction makes financial sense.

California taxes all capital gains, both short-term and long-term, as ordinary income at rates up to 13.3%, according to the California Franchise Tax Board. A California resident in the top bracket already faces a combined federal and state marginal rate exceeding 37% on long-term gains today. Post-2025, that combined rate could approach 40% or higher.

For a California-based investor realizing $5M in long-term gains, the state tax alone exceeds $665,000. That is not a rounding error. It is a number that warrants a serious conversation about domicile, particularly for investors who have already achieved liquidity and have flexibility in where they establish primary residence.

For investors considering international options, understanding countries with favorable capital gains treatment is worth a dedicated analysis, though the U.S. taxes citizens on worldwide income regardless of residency.

Tax Impact Scenarios: $5M Asset Sale in 2025 vs. 2026

The following scenarios assume a married filing jointly investor with $5M in long-term capital gains, no other significant income adjustments, and the gain fully subject to the 20% rate and NIIT. State taxes use California and Florida as contrasting examples.

The middle scenario reflects the bracket compression effect alone. The third scenario reflects a more aggressive legislative outcome that some analysts consider possible but not the baseline. The honest answer is that the exact 2026 outcome remains uncertain. What is not uncertain is that the current window is more favorable than the projected alternatives.

How the TCJA Sunset Affects Investors with Large Unrealized Gains

The stepped-up basis rule under IRC Section 1014 remains one of the most powerful tools for investors holding highly appreciated assets. At death, heirs receive a cost basis equal to fair market value, effectively eliminating embedded capital gains. This provision was not modified by the TCJA and is not scheduled to change in 2026, though it has been a recurring legislative target.

For FATFIRE investors holding concentrated positions in appreciated stock, real estate, or private equity, this creates a legitimate strategic alternative: hold and bequeath rather than sell during your lifetime. If 2026 brings higher effective rates, the calculus tilts further toward holding.

This is not a strategy for everyone. Concentration risk, estate liquidity needs, and the probability that Congress eventually eliminates or limits stepped-up basis all factor into the analysis. But for investors with diversified income sources who do not need to liquidate appreciated positions, the stepped-up basis rules deserve explicit modeling alongside any harvesting strategy.

For investors exploring strategies to minimize capital gains taxes before the sunset, the interaction between stepped-up basis, charitable giving, and timing of sales is where the real planning leverage sits.

Business Exit Timing: The Highest-Stakes Decision Before 2026

For business owners and entrepreneurs, the TCJA sunset creates a compounding risk that deserves its own analysis.

A business sale closing after January 1, 2026 could be taxed under a less favorable rate structure. For a $10M business sale generating $8M in long-term capital gain, the difference between a 2025 close and a 2026 close under a higher effective rate regime could represent $200,000 to $400,000 in additional federal tax alone, depending on the final legislative outcome.

M&A timelines typically span 12 to 18 months. A deal initiated in mid-2024 may have limited flexibility on closing date. Advisors should model both scenarios explicitly now, not in Q4 2025.

Mitigation tools worth evaluating:

• Installment sales under IRC Section 453, which spread gain recognition across multiple years and allow some portion to fall into post-2026 tax years if rates do not materialize as projected
• Qualified Opportunity Zone investments under IRC Sections 1400Z-1 and 1400Z-2, which allow deferral of recognized gains by reinvesting in designated opportunity funds within 180 days
• Charitable remainder trusts, which allow sale of appreciated assets without immediate capital gains recognition, providing an income stream and charitable deduction

One specific QOZ issue deserves attention. Investors who used QOZ investments to defer gains from 2021 through 2023 face a mandatory recognition event by December 31, 2026, the statutory deferral deadline. Those deferred gains will be recognized in 2026 under whatever rate structure exists at that time. If you are in this position, model whether early exit from the QOZ fund before year-end 2025 is preferable to mandatory recognition in 2026 under potentially higher rates.

Tax Optimization Strategies for High-Net-Worth Investors Before the Sunset

The planning window is 2024 and 2025. Here are the strategies with the most direct application for investors at this level.

Accelerate gain recognition selectively. For positions where you intended to sell within the next three to five years anyway, the current rate structure is the known quantity. Post-2025 is not. Partial harvesting of gains in 2024 and 2025 locks in current rates without requiring full liquidation.

Systematic tax-loss harvesting. Vanguard research demonstrates that systematic tax-loss harvesting can add meaningful after-tax alpha annually for taxable investors, with the benefit most pronounced during periods of elevated volatility and for investors in the highest marginal tax brackets. At $5M+ in taxable assets, this is not a retail strategy. It requires coordination across your full portfolio to avoid wash-sale violations and to ensure losses are harvested against the right gain categories.

Donor-advised funds and charitable remainder trusts. Contributing appreciated securities to a donor-advised fund eliminates the capital gains recognition event entirely while generating a charitable deduction at fair market value. For investors with philanthropic intent, this is a structurally superior approach to selling and donating cash. Charitable remainder trusts add an income stream component and are particularly effective for large concentrated positions.

Roth conversion planning. Research published in the Journal of Financial Planning indicates that coordinated asset location, tax-loss harvesting, and strategic Roth conversion planning can reduce lifetime tax liability by hundreds of thousands of dollars for high-net-worth households facing bracket changes. The logic: converting traditional IRA assets to Roth at current ordinary income rates, before those rates potentially rise in 2026, can be advantageous for investors with long time horizons. This requires careful modeling of the conversion amount against your current marginal rate and projected future rates. For a deeper look at how retirement accounts interact with capital gains, see 401k capital gains tax rules.

Trust structures. Irrevocable trusts, grantor retained annuity trusts (GRATs), and other vehicles can shift appreciated assets out of your taxable estate while managing gain recognition timing. The capital gains tax implications for trusts are distinct from individual taxation and require dedicated analysis. Trusts reach the top capital gains rate at very low income thresholds, so asset location within trust structures matters considerably.

Real estate strategies. For investors holding investment properties, 1031 exchanges remain a powerful deferral tool. Capital gains tax on investment properties involves depreciation recapture at 25%, which does not benefit from the preferential long-term rates and is often overlooked in planning conversations. If you are considering a property sale, the depreciation recapture component deserves explicit modeling alongside the capital gains component.

For a broader framework on tax planning strategies when you stop earning, the interaction between capital gains, ordinary income, and estate planning becomes the central planning challenge once you are no longer generating W-2 income.

The 3.8% Net Investment Income Tax: The Rate That Never Goes Away

The NIIT under IRC Section 1411 is structurally separate from the TCJA debate and is not scheduled to change in 2026. It applies to net investment income for single filers with modified adjusted gross income above $200,000 and married filers above $250,000.

Those thresholds have never been inflation-adjusted since the NIIT was enacted in 2013. In real terms, they are significantly lower today than when the law was written. The NIIT now captures a far broader swath of upper-income investors than originally intended, and for FATFIRE investors, it is essentially a permanent add-on.

Any projection of your effective 2026 capital gains rate that does not include the NIIT is incomplete. The true top federal rate on long-term gains is 23.8%, not 20%. This does not change with the TCJA expiration. What changes is the threshold at which the 20% base rate applies, due to bracket compression.

The NIIT also applies to passive income from partnerships, S-corporations, and rental activities, which is relevant for investors with private equity allocations or real estate portfolios. Active participation rules and material participation tests can affect whether specific income streams are subject to the NIIT, and this is worth reviewing with your tax attorney before year-end.

International and Mobility Considerations for Globally-Mobile Investors

For investors with flexibility in where they live, the state tax differential is substantial enough to warrant serious analysis. The difference between California (13.3% state rate) and Florida or Texas (0%) on a $10M gain is $1.33M in state tax. That is not a lifestyle decision. It is a financial one.

Establishing genuine domicile in a no-income-tax state requires more than renting an apartment. California's Franchise Tax Board is aggressive about auditing high-income taxpayers who claim to have left the state, particularly when the taxpayer retains California property, business interests, or family ties. The standard requires demonstrating that you have abandoned California domicile, not merely that you spend fewer than 183 days there.

For investors considering international relocation, the U.S. taxes citizens on worldwide income regardless of physical residence. Renouncing citizenship triggers the expatriation tax under IRC Section 877A, which treats all appreciated assets as sold at fair market value on the day before expatriation. For investors with large unrealized gains, this is a significant exit cost that requires modeling before any decision is made.

Understanding non-resident capital gains tax obligations is relevant for investors who hold U.S. assets while residing abroad, as well as for foreign nationals investing in U.S. markets.

The Legislative Uncertainty Factor: Scenario Planning, Not Prediction

The honest framing is this: no one knows exactly what the 2026 capital gains tax brackets will look like. The TCJA sunset is the baseline, but Congress has intervened before and could do so again. The political composition of the legislature after 2024 elections, deficit reduction pressures, and the economic environment at the time will all influence the outcome.

The Tax Policy Center estimates that the top 1% of earners receive a disproportionate share of the tax benefit from preferential long-term capital gains rates, making the TCJA sunset particularly consequential for high-net-worth investors. That political dynamic creates pressure for higher rates, not lower ones.

Three scenarios worth modeling explicitly:

1. Full TCJA sunset, no new legislation. Ordinary income brackets compress, pushing more gains to the 20% tier. Top effective federal rate remains 23.8% but affects more investors. This is the current baseline.

2. Partial extension. Congress extends some TCJA provisions but allows others to expire. The capital gains bracket thresholds could be partially preserved. Probability is genuinely uncertain and depends heavily on post-2024 political composition.

3. New legislation with higher rates. A top long-term capital gains rate of 25% or 28% has appeared in various legislative proposals. Combined with NIIT, this would produce a top federal rate of 28.8% to 31.8%. This is not the baseline scenario but is not implausible.

For historical capital gains tax trends and how rate changes have affected revenue and investor behavior in past cycles, the data provides useful context for evaluating these scenarios. Historical evidence suggests that large rate increases tend to reduce realization events, which can actually reduce near-term revenue despite higher rates.

For investors curious about unrealized gains taxation proposals that have circulated in policy discussions, these remain politically difficult to implement and are not part of the TCJA sunset mechanics, but they represent a longer-term legislative risk worth monitoring.

Key Planning Milestones: 2024 Through 2026

The planning window is shorter than it appears. Here are the critical dates and decision points.

Now through December 31, 2024. Review your full portfolio for positions where gain realization in 2024 makes sense given your current rate and projected 2026 exposure. Identify tax-loss harvesting opportunities to offset any accelerated gains. Begin modeling business exit scenarios if a transaction is on the horizon.

Q1 through Q2 2025. The legislative picture for TCJA extension should be clearer after the new Congress is seated. Use this window to finalize decisions on large transactions. M&A processes initiated in early 2025 have a reasonable chance of closing before year-end. QOZ investors with 2021 deferred gains should model early exit versus mandatory 2026 recognition.

Q3 through Q4 2025. Final window for Roth conversions, charitable giving strategies, and gain acceleration at current rates. Year-end 2025 is the last opportunity to realize gains under the current bracket structure with certainty.

2026 and beyond. If legislation has not extended TCJA provisions, the new bracket structure applies to all transactions from January 1, 2026. Strategies shift toward deferral, stepped-up basis planning, and tax-efficient ETF taxation complexities for ongoing portfolio management.

The investors who will be best positioned are not the ones who wait for certainty. Certainty will not arrive before the deadline. The ones who benefit are those who model the scenarios now, identify which transactions are rate-sensitive, and execute within the current window while maintaining flexibility for the rest.

References

• Internal Revenue Service -- "Revenue Procedure 2024-40: 2025 Inflation Adjustments for Tax Provisions" (2024)
• Internal Revenue Service -- "Publication 550: Investment Income and Expenses" (2024)
• Tax Foundation -- "Tracking the TCJA Sunset: What Expires in 2026 and What It Means for Taxpayers" (2024)
• Congressional Budget Office -- "The Budget and Economic Outlook: 2024 to 2034" (2024)
• Internal Revenue Code -- "IRC Section 1(h): Maximum Capital Gains Rate"
• Internal Revenue Code -- "IRC Section 1411: Imposition of Tax on Net Investment Income"
• Tax Policy Center (Urban Institute & Brookings Institution) -- "How Does the Current Tax System Affect High-Income Taxpayers?" (2024)
• Vanguard -- "Tax-Loss Harvesting: A Portfolio and Wealth Planning Perspective" (2023)
• Journal of Financial Planning -- "Optimal Asset Location and Tax-Efficient Withdrawal Strategies for High-Net-Worth Clients" (2023)
• California Franchise Tax Board -- "2024 California Capital Gains Tax Rates and Instructions" (2024)