How to Report Investment Income on Your Tax Return

To report investment income on your tax return, transfer the figures from your year-end 1099 forms onto the right schedules behind Form 1040: interest and dividends go on Schedule B, and sales of stocks, funds, and similar assets go on Form 8949 with the totals summarized on Schedule D. Higher earners may owe an additional 3.8% surtax on top of the regular rates, and anyone with foreign accounts has separate filings to make.

The 1099 Forms You’ll Work From

Banks and brokers are required to report what they pay you directly to the IRS, and they send you copies of those reports on 1099 forms.1Office of the Law Revision Counsel. 26 USC 6049 – Returns Regarding Payments of Interest The four you’re most likely to see:

1099-INT and 1099-DIV are due to you by January 31; 1099-B has a later deadline of February 15 (February 17 for 2026 filings).5Internal Revenue Service. General Instructions for Certain Information Returns (2025) Wait for all of them before filing. Because the IRS gets a copy of every 1099, a mismatch between your return and what your broker reported will trigger an automated notice.

Corrected 1099s are common in brokerage accounts. If one arrives after you’ve already filed and the numbers have changed, file an amended return on Form 1040-X.6Internal Revenue Service. Topic No. 154, Form W-2 and Form 1099-R If you traded heavily during the year, waiting until mid-February or later before filing can save you the trouble.

Interest and Dividends on Schedule B

Interest and dividends both live on Schedule B. You have to file it if your taxable interest or your ordinary dividends came to more than $1,500 for the year.7Internal Revenue Service. 2025 Instructions for Schedule B (Form 1040) Below that threshold, the amounts still go on Form 1040 directly; you just skip the schedule.

Interest in Part I

List each payer and the amount from Box 1 of the matching 1099-INT. Tax-exempt interest, usually from municipal bonds and shown in Box 8, goes on a separate line of Form 1040 and doesn’t add to taxable income, but you still report it because it feeds into other calculations.7Internal Revenue Service. 2025 Instructions for Schedule B (Form 1040)

Dividends in Part II

Ordinary dividends from Box 1a of each 1099-DIV go in Part II, listed by payer. Within that Box 1a total, the amount in Box 1b is the qualified portion, taxed at long-term capital gains rates of 0%, 15%, or 20% instead of your ordinary income rate.8Internal Revenue Service. Topic No. 404, Dividends and Other Corporate Distributions Make sure that qualified amount carries through correctly to your Form 1040, because the difference in tax can be substantial.

Mutual fund capital gain distributions, reported in Box 2a of 1099-DIV, are treated as long-term gains no matter how long you’ve held the fund.9Internal Revenue Service. Instructions for Form 1099-DIV They go on Schedule D, not Schedule B.

Sales on Form 8949 and Schedule D

Every sale of a stock, bond, or fund share belongs on Form 8949, and the totals flow to Schedule D.10Internal Revenue Service. 2025 Instructions for Schedule D (Form 1040) Capital Gains and Losses For each transaction, you need three numbers from your 1099-B:

  • The sale proceeds you received.
  • Your cost basis, meaning what you paid, plus any fees or commissions.
  • The dates you bought and sold.

Proceeds minus basis gives you the gain or loss. Each sale gets its own line on Form 8949, and transactions are grouped by whether the broker reported basis to the IRS.11Internal Revenue Service. Instructions for Form 8949 (2025)

Which Shares Did You Sell?

If you bought the same investment at different times and prices, you need a consistent rule for identifying which shares went out the door. First-in-first-out treats the oldest shares as sold first. Specific identification lets you designate the exact lots. For mutual fund shares, you can also use the average cost method, which spreads your total investment across all shares to get one per-share basis.12Internal Revenue Service. Mutual Funds (Costs, Distributions, Etc.) 1 The choice can change the size of the gain or loss you report.

Short-Term Versus Long-Term

How long you held the investment sets the rate. One year or less is short-term, taxed at your ordinary income rates, which run from 10% to 37% for 2026.13Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 More than one year is long-term, taxed at 0%, 15%, or 20% depending on your taxable income.14Internal Revenue Service. Topic No. 409, Capital Gains and Losses

For 2026, a single filer pays 0% on long-term gains up to $49,450 of taxable income, 15% from there to $545,500, and 20% above. Married couples filing jointly get the 0% rate up to $98,900, 15% up to $613,700, and 20% beyond.

When Losses Exceed Gains

On Schedule D, losses first offset gains dollar for dollar. If losses still exceed gains after that netting, you can deduct up to $3,000 of the remainder against ordinary income like wages ($1,500 if married filing separately).15Office of the Law Revision Counsel. 26 USC 1211 – Limitation on Capital Losses Anything above that carries forward to future years with no expiration.

Watch the Wash Sale Rule

Sell an investment at a loss and buy a substantially identical one within 30 days, either before or after the sale, and the loss isn’t deductible on this year’s return.16Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities The disallowed loss isn’t lost outright; it’s added to the basis of the replacement shares, so you get the benefit whenever you eventually sell those. Brokers flag wash sales on Form 1099-B, and you enter the adjustment in the designated column on Form 8949.11Internal Revenue Service. Instructions for Form 8949 (2025) The 30 days runs in both directions, so a purchase 30 days before your loss sale triggers the rule just as easily as one 30 days after.

The 3.8% Net Investment Income Tax

Beyond the regular rates, higher earners owe an additional 3.8% Net Investment Income Tax on top. It applies to the lesser of your net investment income or the amount by which your modified adjusted gross income exceeds these thresholds:17Internal Revenue Service. Topic No. 559, Net Investment Income Tax

  • $200,000 for single filers and heads of household.
  • $250,000 for married filing jointly.
  • $125,000 for married filing separately.

Net investment income here means interest, dividends, capital gains, rental income, royalties, and similar categories. The thresholds don’t adjust for inflation, so more taxpayers cross them each year. If the tax applies to you, calculate it on Form 8960 and attach that form to your return.18Internal Revenue Service. About Form 8960, Net Investment Income Tax Individuals, Estates, and Trusts

Do You Need to Pay Estimated Tax During the Year?

Investment income usually isn’t subject to withholding. If yours is significant, say a large capital gain from a stock sale or substantial dividends, you may owe quarterly estimated payments rather than a single check at filing time. For 2026, the four due dates are April 15, June 15, September 15, and January 15, 2027.19Internal Revenue Service. Form 1040-ES Estimated Tax for Individuals

You generally avoid an underpayment penalty if your total withholding and estimated payments cover at least 90% of the current year’s tax or 100% of last year’s tax, whichever is smaller. If your prior-year adjusted gross income topped $150,000 ($75,000 if married filing separately), the prior-year safe harbor is 110% instead.19Internal Revenue Service. Form 1040-ES Estimated Tax for Individuals Come up short and the IRS calculates a penalty on Form 2210.20Internal Revenue Service. Underpayment of Estimated Tax by Individuals, Estates, and Trusts

Foreign Accounts Have Their Own Filings

If any of your investment accounts sit outside the United States, the 1099 workflow above doesn’t cover you fully. Two separate filings may apply, both with steep penalties for skipping them.

An FBAR (FinCEN Form 114) is required if the combined value of your foreign financial accounts exceeded $10,000 at any point during the year. You file it electronically with FinCEN, not with your tax return.21FinCEN.gov. Report Foreign Bank and Financial Accounts The due date is April 15, with an automatic extension to October 15; no request needed.22Internal Revenue Service. Report of Foreign Bank and Financial Accounts (FBAR)

Form 8938 is a separate FATCA filing that attaches to your tax return. For taxpayers living in the U.S., single filers must file if foreign financial assets exceeded $50,000 on the last day of the year or $75,000 at any point during it; the thresholds are $100,000 and $150,000 for married couples filing jointly.23Internal Revenue Service. Summary of FATCA Reporting for U.S. Taxpayers Form 8938 covers a wider range of assets than the FBAR, including foreign stock and securities held outside a financial account, so filing one does not satisfy the other.

Bringing It Together on Form 1040

Once the schedules are done, the totals flow onto the main form. Tax software handles the integration automatically and cross-checks Schedule B, Schedule D, Form 8949, and any other attachments against each other before you file. On a paper return, stack the schedules behind Form 1040 in the order the IRS specifies. Most states tax investment income too, so check whether your state return needs its own schedules for the same transactions.