The typical investor pays one of three different tax rates on the same dollar of profit — depending solely on how that profit was earned. Get this right and you keep thousands more per year. Get it wrong and you hand the IRS more than your fair share without realising it.
This guide breaks down exactly how the IRS taxes capital gains, dividends, and interest income — with the 2025 numbers — and what you can do to keep more of what you earn.
The Three Types of Investment Income
Not all investment income is treated equally by the tax code. There are three main categories, each with its own rate structure.
1. Capital Gains
A capital gain occurs when you sell an investment for more than you paid. The tax rate depends on how long you held it:
Short-term capital gains (held 1 year or less): Taxed as ordinary income, at your regular federal income tax bracket — anywhere from 10% to 37%.
Long-term capital gains (held more than 1 year): Taxed at preferential rates of 0%, 15%, or 20% depending on your income.
This difference is enormous. If you're in the 22% income tax bracket and sell a stock you've held for 8 months, you'll owe 22% on the gain. Hold it for 12 months and one day, and that rate drops to 15%. On a $20,000 gain, that's $1,400 in savings for simply waiting.
2025 Long-Term Capital Gains Tax Brackets
| Filing Status | 0% Rate | 15% Rate | 20% Rate |
|---|---|---|---|
| Single | Up to $47,025 | $47,026–$518,900 | Above $518,900 |
| Married Filing Jointly | Up to $94,050 | $94,051–$583,750 | Above $583,750 |
| Head of Household | Up to $63,000 | $63,001–$551,350 | Above $551,350 |
Many middle-income investors qualify for the 0% long-term capital gains rate. If your taxable income is below $94,050 (married filing jointly), you can realise gains and owe nothing federally — a powerful but underused opportunity.
2. Dividends
Dividends are split into two categories:
Qualified dividends: Taxed at the same preferential long-term capital gains rates — 0%, 15%, or 20%. To qualify, the dividend must come from a U.S. corporation or qualifying foreign corporation, and you must have held the stock for more than 60 days during the 121-day window surrounding the ex-dividend date.
Ordinary dividends: Taxed as regular income — the same rates as your salary or wages.
Most dividends from major U.S. stocks and index funds are qualified. REITs, however, typically pay ordinary dividends taxed at full income rates, which is why holding them in a tax-advantaged account like a Roth IRA makes particular sense.
3. Interest Income
Interest from savings accounts, CDs, bonds, and money market accounts is taxed as ordinary income — no preferential rates. That means it's taxed at your marginal rate, up to 37%.
One notable exception: interest from U.S. Treasury bonds and savings bonds is exempt from state income tax (but not federal). Municipal bond interest is typically exempt from federal income tax and, if the bond was issued in your home state, exempt from state tax too — making munis especially attractive for investors in high-tax states like California or New York.
The Net Investment Income Tax (NIIT)
High-income earners face an additional 3.8% surtax on most investment income. This applies to the lesser of your net investment income or the amount your modified adjusted gross income (MAGI) exceeds:
- $200,000 for single filers
- $250,000 for married filing jointly
So if you're a married couple with $300,000 MAGI and $30,000 in investment income, the NIIT applies to $30,000 — adding an extra $1,140 to your tax bill. Combined with the 20% top long-term capital gains rate, the effective top rate on investment income is 23.8%.
This threshold is not indexed for inflation, meaning more investors fall into NIIT territory each year without any change in their real purchasing power.
What Tax Forms to Expect
Your brokerage is required to report investment income to the IRS and send you matching forms by mid-February:
| Form | What It Reports |
|---|---|
| 1099-B | Sales of stocks, bonds, and mutual funds |
| 1099-DIV | Dividend and capital gain distributions |
| 1099-INT | Interest income |
| 1099-OID | Original issue discount (certain bonds) |
If you have accounts at multiple brokerages, you'll receive multiple 1099s. Don't file until they all arrive — 1099s are sometimes corrected after the initial issue date, and amended returns delay any refund and attract scrutiny.
5 Strategies to Reduce Investment Taxes Legally
1. Hold Investments for More Than a Year
The simplest and most impactful move: wait 12+ months before selling. The difference between short-term and long-term rates can easily be 15–22 percentage points. On a $50,000 gain, that's $7,500 to $11,000 in savings — just for being patient.
This is why frequent trading is expensive beyond commissions. Every short-term sale converts preferential rates into ordinary income rates.
2. Max Out Tax-Advantaged Accounts
Investments inside a Roth IRA or Roth 401(k) grow completely tax-free — no capital gains tax, no dividend tax, no NIIT. Ever. A traditional IRA or 401(k) defers taxes until withdrawal, but eliminates tax drag during the compounding years.
The strategic move: hold your highest-growth assets (small-cap stocks, REITs, high-dividend funds) inside tax-advantaged accounts where the gains compound untouched. Put your tax-efficient investments (broad index funds, buy-and-hold stocks) in taxable accounts where turnover is low anyway.
3. Tax-Loss Harvesting
If some of your investments have dropped in value, you can sell them to realise a loss that offsets your gains. The rules:
- Capital losses offset capital gains dollar-for-dollar
- If your losses exceed your gains, you can deduct up to $3,000 against ordinary income per year
- Additional losses carry forward indefinitely to future tax years
- Watch out for the wash-sale rule: you cannot buy the same or substantially identical security within 30 days before or after the sale, or the loss is disallowed
The workaround: sell a losing S&P 500 ETF and immediately buy a total market ETF from a different fund family. Your market exposure stays intact while you bank the loss.
4. Qualify for the 0% Capital Gains Rate
If your income is near the threshold, it may be worth deliberately realising gains in a year when your taxable income falls below the 0% bracket cutoff — $94,050 for married couples in 2025. This is sometimes called "gain harvesting."
Coordinate salary, retirement contributions, itemised deductions, and investment income carefully. For early retirees or people between jobs, this window can be wide open and valuable.
5. Donate Appreciated Stock Instead of Cash
If you give to charity, donate appreciated shares directly rather than selling and donating the proceeds. You receive a deduction for the full fair market value of the shares, and neither you nor the charity pays capital gains tax on the built-in appreciation. It's a double tax benefit compared to the sell-and-donate approach.
On a $10,000 stock position with an $8,000 gain, the traditional route costs you $1,200 in federal taxes (at 15%) before the donation. The direct-donation route costs you nothing.
A Quick Example: Same $10,000 Gain, Three Tax Bills
| Scenario | Rate Applied | Tax Owed |
|---|---|---|
| Short-term gain, 24% bracket | 24% ordinary income | $2,400 |
| Long-term gain, 15% bracket | 15% preferential | $1,500 |
| Long-term gain, 0% bracket | 0% preferential | $0 |
The investor in the 0% scenario keeps $2,400 more than the short-term seller — from an identical investment return. The only variable is how long they held it and what their income was.
State Taxes on Investment Income
Federal rates get most of the attention, but state taxes matter too. Most states tax capital gains as ordinary income at rates ranging from 0% (Texas, Florida, Nevada, Washington) to 13.3% in California. California also doesn't offer preferential treatment for long-term gains — they're taxed at the same rate as wages.
If you live in a high-tax state and have significant gains to realise, the combined federal-plus-state burden can approach 35–40% on short-term gains for top earners. This makes account type selection and holding period decisions even more important.
When to Pay Estimated Taxes
If you have significant investment income not subject to withholding, you may need to make quarterly estimated tax payments to the IRS. The due dates for 2025 are:
- April 15 (Q1)
- June 16 (Q2)
- September 15 (Q3)
- January 15, 2026 (Q4)
Failing to pay enough throughout the year triggers an underpayment penalty — even if you pay in full when you file. The safe harbour: pay at least 100% of last year's tax liability (or 110% if your prior-year AGI exceeded $150,000), and you'll avoid penalties regardless of what you owe at filing.
The Bottom Line
Investment income isn't taxed uniformly, and the differences are worth thousands of dollars per year. Long-term capital gains and qualified dividends get preferential rates of 0%, 15%, or 20%. Interest income is taxed as regular income. High earners pay an additional 3.8% NIIT on top of those rates.
The biggest levers to reduce your tax bill: hold positions for at least a year, max out tax-advantaged accounts, harvest losses strategically, and consider donating appreciated stock instead of cash.
To see exactly how after-tax returns affect your long-term wealth, use the Compound Interest Calculator — it shows what your investment actually compounds to once taxes take their cut.