The 0% Capital Gains Bracket: Pay Zero Tax on Gains

Most tax planning conversations focus on avoiding taxes by deferring income or maximizing deductions. But there's a quieter strategy that works in the opposite direction: deliberately realizing gains when your income is low enough to keep them in the 0% long-term capital gains bracket.

This approach, often called tax gain harvesting, is particularly powerful for early retirees, people in bridge years between full-time work and Social Security, or anyone who has stepped back from a high-earning career. If your taxable income falls below the annual threshold, you can sell appreciated stock, mutual funds, or ETFs held for more than one year and owe nothing in federal capital gains tax on those profits.

The catch? A few important interactions with Social Security taxation and ACA health insurance subsidies mean this strategy requires careful income math before you act. This guide walks through how the bracket works, illustrates the math with hypothetical scenarios, and highlights the thresholds worth watching in 2026.

The IRS taxes long-term capital gains - profits from assets held more than one year - at separate, generally lower rates than ordinary income. For 2026, the three federal rates are 0%, 15%, and 20%, with an additional 3.8% Net Investment Income Tax (NIIT) applying to higher earners. The 0% rate applies to taxpayers whose taxable income (after deductions) falls below set annual thresholds.

For 2025, the IRS set the 0% bracket at taxable income up to $48,350 for single filers and $96,700 for married couples filing jointly (IRS Revenue Procedure 2024-40). The 2026 figures will be inflation-adjusted and published by the IRS - it's worth confirming the exact numbers before you act. Historically, these thresholds have risen modestly each year in line with inflation adjustments.

Here is the critical nuance: capital gains are stacked on top of ordinary income for purposes of determining which rate applies. Your ordinary income fills the lower portion of the taxable income ladder first, and your capital gains sit above it. So the question isn't simply whether your gains are below the threshold. It's whether your total taxable income, including those gains, stays below the threshold.

A practical illustration: if a hypothetical single retiree has $30,000 in ordinary income after the standard deduction, they have approximately $18,350 of room left before hitting the 0% bracket ceiling (based on 2025 figures). Realizing up to $18,350 in long-term gains would cost nothing in federal capital gains tax. Realizing $20,000 would push $1,650 into the 15% bracket, costing $248 - still modest, but worth knowing in advance.

You may be familiar with tax-loss harvesting, where investors sell positions at a loss to offset gains elsewhere. Tax gain harvesting is the mirror image: selling positions at a gain when your tax rate on those gains is zero, then immediately repurchasing the same or similar investments.

The result is a higher cost basis in your portfolio with no tax owed today. A higher cost basis means smaller taxable gains when you eventually sell those assets in a higher-income year. In effect, you are banking a future tax saving during a low-tax window.

Consider a hypothetical example. Suppose a 58-year-old early retiree, call her Maria, retired two years ago and currently lives on modest withdrawals from a taxable brokerage account. She holds shares of a broad market index fund she bought years ago at $40 per share. They are now worth $90 per share, meaning she has $50 of unrealized gain per share.

• If Maria sells 300 shares this year while her taxable income is below the 0% threshold, she realizes $15,000 in gains and owes zero federal capital gains tax.
• She immediately repurchases 300 shares at $90. Her new cost basis is $90 per share instead of $40.
• When she later sells those shares at, say, $120, she owes gains tax only on the $30 difference, not the full $80 increase from her original purchase price.

The IRS wash-sale rule - which disallows certain loss deductions when you repurchase a substantially identical security within 30 days - does not apply to gains. Gain harvesting does not trigger wash-sale concerns, which is one reason the strategy is structurally clean when executed carefully.

The practical goal is to identify exactly how much room you have in the 0% bracket before triggering gains. This requires stacking your income sources carefully. Here is a general framework many tax planners use to think through the calculation - though the specific numbers in your situation will differ, and a tax professional can help model your exact position.

Hypothetical Scenario 1: Married couple, both 62, not yet claiming Social Security

• Pension income: $40,000
• IRA distributions: $20,000
• Standard deduction (2025, MFJ): $30,000
• Taxable income before gains: $30,000
• Room remaining in 0% bracket (based on 2025 threshold): approximately $66,700
• Potential tax-free gain harvesting: up to approximately $66,700 in long-term gains

Hypothetical Scenario 2: Single filer, age 56, early retiree living on brokerage withdrawals

• Brokerage account principal withdrawals (not taxable): $25,000
• Part-time consulting income: $18,000
• Standard deduction (2025, single): $15,000
• Taxable income before gains: $3,000
• Room remaining in 0% bracket: approximately $45,350
• Potential tax-free gain harvesting: up to approximately $45,350 in long-term gains

These examples are illustrative only and use 2025 figures as a reference point. Real situations vary significantly based on filing status, deductions, state taxes, and the composition of income. The important discipline is to total all income sources first before deciding how much gain to realize, rather than estimating loosely and risking a spill into the 15% bracket.

For a broader picture of your retirement income streams, tools like a retirement income planner can help you map out all sources before running the gain-harvesting math.

Tax gain harvesting does not happen in a vacuum. Realized capital gains count as income in two calculations that can significantly affect retirees: the taxation of Social Security benefits and eligibility for ACA marketplace premium tax credits.

Social Security Benefit Taxation

If you are already claiming Social Security, realized gains increase your combined income (also called provisional income), which is used to determine how much of your Social Security benefit is taxable. Under IRS rules, up to 50% of your Social Security benefit becomes taxable when combined income exceeds $25,000 for single filers ($32,000 for married filing jointly), and up to 85% becomes taxable above $34,000 ($44,000 for married filing jointly). Realizing a large capital gain in a year when you are collecting Social Security could inadvertently push more of your benefit into taxable territory, partially or fully offsetting the value of the 0% gains rate.

ACA Premium Tax Credits

For retirees under 65 who rely on the Affordable Care Act marketplace for health insurance, this interaction deserves particular attention. ACA premium tax credits are based on your modified adjusted gross income (MAGI) relative to the federal poverty level. Realized capital gains increase MAGI, which can reduce or eliminate your subsidy. Depending on your subsidy amount, a large gain harvest could cost more in lost ACA credits than you save in capital gains taxes. Modeling this tradeoff carefully - ideally with a tax professional familiar with ACA subsidy cliffs - is worth the effort before acting. You can read more about healthcare costs in the pre-Medicare years in our guide to healthcare planning for early retirees.

State Taxes

The 0% federal rate does not automatically apply at the state level. Many states tax capital gains as ordinary income, with no equivalent 0% bracket. States including California, New York, and Oregon tax long-term gains at ordinary income rates. If you live in a state with capital gains taxation, the net benefit of gain harvesting is reduced, though often still positive depending on your state rate and the size of the gain.

IRMAA for Medicare

If you are already on Medicare, high realized income - including capital gains - can trigger Income-Related Monthly Adjustment Amounts (IRMAA), which increase your Part B and Part D premiums. IRMAA uses income from two years prior, so a large gain-harvesting year in 2026 could affect your 2028 Medicare premiums. This is a lesser concern for early retirees not yet on Medicare, but it's worth flagging for those who are.

This strategy tends to be most relevant in specific life circumstances where income dips below the normal thresholds:

• The gap years between retirement and Social Security. Many early retirees retire in their late 50s or early 60s but delay Social Security to maximize their eventual benefit. Before Social Security begins, income is often at its lowest, creating a natural window for gain harvesting.
• A sabbatical, career break, or partial retirement year. A year with significantly lower earned income may create bracket room that wouldn't otherwise exist.
• After a large deduction year. Years with unusually high deductible expenses (medical costs, large charitable contributions, business losses) can lower taxable income and create extra room in the 0% bracket.
• Before Roth conversions increase income in later years. If you plan to do Roth conversions in future years, harvesting gains now - before Roth conversion income occupies the bracket - can be a useful sequencing choice to consider with a tax adviser.

The strategy is generally less relevant in years when income is high, when Social Security or large IRA distributions already consume most of the bracket, or when state taxes eliminate most of the federal benefit.

Disclaimer: This article is intended for general educational purposes only and does not constitute personalised financial, tax, or investment advice. Tax rules are subject to change, and the thresholds referenced reflect 2025 IRS guidance as a reference point. The 2026 figures will be formally published by the IRS. Every financial situation is different. Please consult a qualified financial adviser, CPA, or tax professional before making any decisions related to capital gains harvesting, retirement income planning, or investment strategy.