Sell a stock, a rental property, or a chunk of a family business, and the IRS wants its cut.
But how big that cut is depends on a number most people never check until it's too late: their taxable income for the year.
Long-term capital gains — assets held more than a year — get friendlier treatment than your paycheck.
For 2025, single filers pay 0% on long-term gains up to $48,350, then 15% up to $533,400, and 20% above that.
Married couples filing jointly get a 0% bracket up to $96,700, 15% up to $600,050, and 20% beyond.
Those thresholds apply to your total taxable income, not just the gain itself.
A gain stacked on top of a solid salary can shove you into a higher bracket than you expected, even if you're nowhere near wealthy.
Short-term gains — anything held a year or less — are taxed as ordinary income.
That means rates from 10% to 37% depending on your bracket.
For a lot of middle-income sellers, simply waiting a few extra weeks to cross the one-year mark can save thousands.
There's also a 3.8% net investment income tax that kicks in once modified adjusted gross income tops $200,000 for singles or $250,000 for couples.
It applies on top of the regular capital gains rate, so high earners can face a combined 23.8%.
Single filers can exclude up to $250,000 of profit on a primary residence, and couples up to $500,000, provided you've lived there two of the past five years.
That exclusion has stayed flat for years even as home prices climbed, which means more sellers now owe tax on gains they assumed were untouchable.
Retirement accounts sidestep the whole mess.
Gains inside a 401(k) or IRA aren't taxed when they happen — only when you withdraw, and then at ordinary income rates.
That's why maxing out tax-advantaged accounts remains the simplest legal shelter for long-term growth.
If you're sitting on a winner you don't need to sell, holding it until retirement or a lower-income year can drop your rate to zero.
Donating appreciated shares to charity is another route that avoids the tax entirely while generating a deduction.
One more trap: mutual funds can hand you a capital gains distribution even if you never sold a thing.
Check your funds before year-end, especially in taxable brokerage accounts.
Your capital gains rate isn't a fixed number — it's a moving target based on timing, income, and where you park your money.
Final Thoughts
A little planning before you sell usually beats a bigger tax bill after.