How Capital Gains Tax Works: Short-Term vs. Long-Term Rates

What Is a Capital Gain?

A capital gain is the profit you realize when you sell a capital asset — such as stocks, bonds, real estate, cryptocurrency, or collectibles — for more than your cost basis (what you originally paid, including commissions and fees). If you bought 100 shares of stock at $40 each and sold them at $65 each, your capital gain is $2,500.

Capital gains are not taxed when the asset merely increases in value on paper — only when you actually sell and realize the gain. This distinction gives investors meaningful control over their tax situation: you can defer taxes indefinitely by continuing to hold an appreciated asset.

Short-Term Capital Gains: Taxed as Ordinary Income

If you sell an asset you have held for one year or less, the profit is a short-term capital gain and is taxed at your ordinary federal income tax rate — the same brackets (10%, 12%, 22%, 24%, 32%, 35%, or 37%) that apply to wages and salary income. This can be a punishing rate for high-income investors in the 32% or 37% brackets.

The one-year threshold is calculated precisely: if you buy on March 15, you must hold until at least March 16 of the following year for the gain to qualify as long-term. Active traders who frequently buy and sell positions face short-term rates on all their gains, which substantially reduces net returns compared to a buy-and-hold approach even if their gross returns are similar.

Long-Term Capital Gains: Preferential Rates

Assets held for more than one year before sale qualify for long-term capital gains tax rates, which are significantly lower than ordinary income rates. For 2025, the three long-term rates are:

• 0%: For single filers with taxable income up to approximately $48,350; married filing jointly up to approximately $96,700.
• 15%: For single filers with taxable income between roughly $48,351 and $533,400; married filing jointly between $96,701 and $600,050.
• 20%: For income above those thresholds.

The difference between a 37% short-term rate and a 20% long-term rate on a $100,000 gain is $17,000 in additional taxes. For many investors, the simple act of holding an investment one day longer — crossing the one-year threshold — produces substantial tax savings.

The 0% Long-Term Rate: An Underused Opportunity

The 0% long-term capital gains rate is one of the most overlooked opportunities in tax planning. Individuals and couples with modest taxable income can sell appreciated assets and pay no federal tax on the gains. This creates powerful planning opportunities:

• Tax-gain harvesting: Selling appreciated assets in low-income years (early retirement, sabbaticals, business loss years) to reset your cost basis higher — completely tax-free — reducing future tax liability.
• Gifting to lower-income family members: Transferring appreciated assets to adult children or parents in the 0% bracket, who can then sell tax-free.
• Strategic Roth conversions: Coordinating income so that capital gains and Roth conversion income together stay within the 0% or 15% long-term bracket.

Net Investment Income Tax (NIIT)

High-income investors face an additional 3.8% Net Investment Income Tax on top of regular capital gains rates. The NIIT applies to the lesser of net investment income or the amount by which modified AGI exceeds $200,000 (single) or $250,000 (married filing jointly). This means the effective top federal rate on long-term capital gains is not 20% but 23.8% for affected taxpayers.

Investment income subject to NIIT includes capital gains, dividends, interest, passive rental income, and income from passive business activities. It does not include wages, Social Security, or income from active business participation. The NIIT has no standard deduction equivalent — it applies dollar-for-dollar above the threshold.

Capital Losses and Tax-Loss Harvesting

Capital losses — realized when you sell an asset for less than your cost basis — offset capital gains. Long-term losses first offset long-term gains, and short-term losses offset short-term gains. After netting within each category, remaining losses cross over. If you have more losses than gains, you can deduct up to $3,000 of net capital losses against ordinary income annually, with any excess carried forward to future years.

Tax-loss harvesting is the deliberate strategy of realizing losses before year-end to offset gains. Robo-advisors like Betterment and Wealthfront automate this process. Be aware of the wash-sale rule: you cannot claim a loss if you buy a substantially identical security within 30 days before or after the sale. You can, however, immediately buy a different but similar ETF (selling VTSAX and buying SCHB, for example) to maintain market exposure without triggering the wash-sale rule.

Special Rules for Real Estate and Other Assets

Real estate held more than one year qualifies for long-term rates, but there is a special wrinkle: depreciation recapture. Any depreciation deductions you claimed while owning rental property are recaptured at a maximum rate of 25% when you sell, regardless of your overall long-term rate. This often surprises real estate investors who assumed their entire gain would be taxed at 15% or 20%.

For your primary residence, a powerful exclusion applies: single filers can exclude up to $250,000 of gain ($500,000 married filing jointly) from the sale of a home lived in for at least 2 of the last 5 years. This exclusion can be used repeatedly throughout your lifetime, making residential real estate one of the most tax-advantaged investments available to ordinary Americans.