If you own a stock, a fund, or a rental property that has climbed in value, the tax you eventually pay on the gain depends on two things: how long you held it and how much other income you reported.
Hold an asset for more than a year and it's taxed under long-term capital gains rates.
Hold it for a year or less and the gain stacks on top of your ordinary income, where the top rate sits at 37% for 2025.
For 2025, the long-term brackets are 0%, 15%, and 20%.
The 0% bracket applies to taxable income up to $48,350 for single filers and $96,700 for married couples filing jointly.
Above those lines, most gains get taxed at 15%.
The top 20% rate kicks in past $533,400 for singles and $600,050 for joint filers, and high earners may also owe the 3.8% net investment income tax on top of that.
Here's the part that surprises people: the brackets are based on your total taxable income, not on the size of the gain by itself.
A retiree living mostly on savings can sell a long-held stock, keep taxable income under the threshold, and pay nothing on the appreciation.
The gain doesn't get ignored — it fills up the bracket along with everything else.
That's also why timing a sale matters more than investors think.
A big Roth conversion, a year-end bonus, or a mutual fund distribution in December can push you past a threshold and turn a 0% gain into a 15% one.
Investors who sell first and check the bracket later sometimes hand over thousands they didn't need to.
First, the 0% rate can still carry a hidden cost: it feeds into the "taxable income" figure used to decide whether your Social Security benefits are taxed and how much you pay for ACA marketplace coverage.
Second, the rate you owe is separate from the 10% early-withdrawal penalty on retirement accounts before age 59½ — that penalty applies to the withdrawal, not to the capital gain.
Bracket thresholds are adjusted for inflation each year, and the current numbers expire after 2025 unless Congress acts.
The IRS has a full breakdown in Publication 550, along with rules on wash sales and how losses offset gains.
The honest takeaway: the 0% bracket is real, but it rewards planning, not hoping.
Final Thoughts
Talk to a tax professional before a large sale, and model the whole year rather than just the trade.