Sell a stock, a rental property, or a chunk of a family business, and the IRS wants its cut.
How big that cut is depends on one thing most investors ignore until April: how long they held the asset.
Miss the one-year mark by even a few days, and the tax bill on the same profit can jump by thousands of dollars.
Short-term gains — assets held a year or less — get taxed as ordinary income.
For a married couple in the 24% bracket, that's 24% off the top.
Hold the same investment for at least a year and a day, and the long-term rate drops to 15% for most filers.
On a $50,000 gain, that's a $4,500 difference for doing nothing but waiting.
The long-term brackets themselves run 0%, 15%, and 20%, depending on taxable income.
Single filers can claim the 0% rate on long-term gains up to roughly $48,000 in 2025, and married couples filing jointly up to about $96,000.
Above those lines, 15% kicks in — and it stays there for most households.
The 20% top rate only hits single filers past about $533,000 and couples past roughly $600,000.
There's a separate 3.8% net investment income tax that catches higher earners: single filers above $200,000 and couples above $250,000.
It stacks on top of the capital gains rate, so a 20% bracket investor can effectively pay 23.8% on the gain.
Sell a rental and you may owe depreciation recapture, taxed at up to 25%, on the portions you wrote off over the years.
That's a line item plenty of landlords discover only at closing.
Timing is the simplest lever most people have.
If a sale would push a gain into a higher bracket, waiting until January can split the income across two tax years.
If a position is sitting at a small loss, dumping it before year-end can offset gains elsewhere in the portfolio and trim the taxable total.
Retirement accounts sidestep the whole question.
Gains inside a 401(k) or IRA aren't taxed as they happen — the account grows untaxed until withdrawals, which are then taxed as ordinary income.
A taxable brokerage account gets no such shield, which is why the holding-period rule matters so much there.
Wash sale rules are the trap in the other direction.
Sell a losing investment and buy it back within 30 days, and the IRS disallows the loss.
The disallowed amount gets folded into the cost basis of the replacement shares, quietly changing the math on a future sale.
There's no universal right answer on when to sell.
But the difference between a 24% and a 15% rate isn't a rounding error — it's real money that stays in a household's pocket or doesn't.
The holding period is the single most controllable piece of the equation, and it costs nothing to use.
Anyone with a sizable position, a rental, or a business stake approaching a sale date should run the numbers before signing, not after.
Final Thoughts
A few hours with a tax professional in the fall can be worth far more than the fee.