Report most sales and other capital transactions on Form 8949, then summarize gains and losses on Schedule D (Form 1040), according to Internal Revenue Service. The California Franchise Tax Board lists Individual Income Tax Return (IRS Form 1040) and Capital Gains and Losses, Schedule D (IRS Form 1040) as the relevant forms, according to California Franchise Tax Board.
Key Takeaways
- Report capital gains and losses on Schedule D (Form 1040), Capital Gains and Losses, where your total net loss appears on line 16 according to the Internal Revenue Service.
- Your annual capital loss deduction is capped at the lesser of $3,000 ($1,500 if married filing separately) or your total net loss according to the Internal Revenue Service.
- For taxable years beginning in 2025, the tax rate on most net capital gain is no higher than 15% for most individuals according to the Internal Revenue Service.
- You cannot deduct losses related to wash sales under Internal Revenue Service rules according to the U.S. Securities and Exchange Commission.
- All taxpayers must report gains and losses from the sale or exchange of capital assets according to the California Franchise Tax Board.
Start your filing process by gathering your brokerage statements and identifying any sales of substantially identical securities within 30 days of a loss to check for wash sales.
How to report capital gains and losses on your tax return
Filing an accurate return starts with choosing the right form for each transaction. The Internal Revenue Service directs taxpayers to report most sales and other capital transactions and calculate capital gain or loss on Form 8949, Sales and Other Dispositions of Capital Assets, then summarize capital gains and deductible capital losses on Schedule D (Form 1040), according to Internal Revenue Service. This two-step process separates the detailed transaction list from the summary that flows into your main return.
You will complete the federal forms first, then carry the results to your state filing.
Start by gathering every brokerage statement and closing document for assets sold during the year. For each sale, you need the date acquired, date sold, sales price, and cost basis. The Internal Revenue Service requires that you report most sales and other capital transactions on Form 8949, according to Internal Revenue Service.
Your first action step: pull your year-end brokerage statements and identify every sale of a capital asset, then sort those transactions by acquisition date and sale date so you can enter them on Form 8949 in the correct order.
A filled reference table for capital gain reporting rules
The table below pulls together the seven items you need to check before filing, each tied to the source that states the rule.
| Item | Rule | Source |
|---|---|---|
| 1. Form selection | Report most sales and other capital transactions and calculate capital gain or loss on Form 8949, then summarize capital gains and deductible capital losses on Schedule D (Form 1040). | Internal Revenue Service |
| 2. Wash sale window | A loss sale within 30 days before or after buying substantially identical stock is a wash sale. | Internal Revenue Service |
| 3. Rule 1 example | A loss disallowed in 2024 under Rule 1 is not allowed in 2025 unless the substantially identical stock or securities that caused the 2024 disallowance were disposed of during 2025. | Internal Revenue Service |
| 4. Annual limit | The excess loss you can claim is the lesser of $3,000 ($1,500 if married filing separately) or your total net loss. | Internal Revenue Service |
| 5. Tax rate cap | For 2025, the tax rate on most net capital gain is no higher than 15% for most individuals. | Internal Revenue Service |
| 6. Basis definition | An asset's basis is generally its cost to the owner; see Publication 551 for gifts or inheritances. | Internal Revenue Service |
| 7. State reporting | All taxpayers must report gains and losses from the sale or exchange of capital assets. | California Franchise Tax Board |
For the wash sale window, according to Internal Revenue Service, the wash sale rules apply to a loss realized on a short sale if you sell, or enter into another short sale of, substantially identical stock or securities within a period beginning 30 days before the date the short sale is complete and ending 30 days after that date.
For the loss carryover row, according to Internal Revenue Service, a loss disallowed in 2024 under Rule 1 will not be allowed in 2025, unless the substantially identical stock or securities (which caused the loss to be disallowed in 2024) were disposed of during 2025.
For the annual limit, according to Internal Revenue Service, if your capital losses exceed your capital gains, the amount of the excess loss that you can claim to lower your income is the lesser of $3,000 ($1,500 if married filing separately) or your total net loss shown on line 16 of Schedule D (Form 1040), Capital Gains and Losses.
Keep this table handy as you work through your return, and verify each item against your own transaction records before you file.
Understanding the wash sale prohibition and its impact
The wash sale rule can block a deduction you expect to take. According to Internal Revenue Service, a wash sale is a sale of stock or securities at a loss within 30 days before or after you buy or acquire in a fully taxable trade, or acquire a contract or option to buy, substantially identical stock or securities. The window matters for short sales too. According to Internal Revenue Service, the wash sale rules apply to a loss realized on a short sale if you sell, or enter into another short sale of, substantially identical stock or securities within a period beginning 30 days before the date the short sale is complete and ending 30 days after that date.
The consequence is direct. According to U.S. Securities and Exchange Commission, Internal Revenue Service rules prohibit you from deducting losses related to wash sales. A concrete example from the IRS shows how the timing rule operates. According to Internal Revenue Service, you cannot deduct the $250 loss ($1,000 − $750) because the date of entering into the short sale (October 15) is considered the date the sale is complete for wash sale purposes and you bought substantially identical stock within 30 days from that date.
If your loss is disallowed, the loss is not gone. According to Internal Revenue Service, if your loss was disallowed because of the wash sale rules, add the disallowed loss to the cost of the new stock or securities. That adjustment raises your basis in the replacement shares, so the economic loss is deferred rather than permanently lost.
For deeper detail, the SEC points to the same source. According to U.S. Securities and Exchange Commission, for more information about wash sales, read IRS Publication 550, Investment Income and Expenses (Including Capital Gains and Losses).
Before you file, review your brokerage statements for any purchase of substantially identical securities within the 30-day window around each loss sale, and check whether you entered or completed any short sales in that same period.
Calculating your net capital gain and applicable tax rates
To calculate your net capital gain, you first total your capital gains and subtract your capital losses for the year. According to FINRA, whereas a capital gain increases your income on your tax return, a capital loss generally counts as a deduction. The result of that subtraction is your net capital gain, and the rate that applies to it depends on your overall taxable income.
The rate is not a single flat number. According to Internal Revenue Service, net capital gains are taxed at different rates depending on overall taxable income, although some or all net capital gain may be taxed at 0%.
There is also an upper bound on the rate for most taxpayers. According to Internal Revenue Service, for taxable years beginning in 2025, the tax rate on most net capital gain is no higher than 15% for most individuals. The 15% figure is the ceiling for most individuals in 2025.
To apply this to your situation, calculate your total gains, subtract your deductible losses. Pull your brokerage statements and total your realized gains and losses for the year before you start filling out your return.
Illustrative example of the annual loss cap
Suppose your total net loss on line 16 of Schedule D (Form 1040) is $3,000. The excess loss you can claim is the lesser of $3,000 ($1,500 if married filing separately) or that net loss. A loss within 30 days of buying substantially identical stock is not deductible.
Handling excess capital losses and carryover rules
When your losses outrun your gains, the IRS puts a hard cap on what you can deduct in a single year. According to Internal Revenue Service, if your capital losses exceed your capital gains, the amount of the excess loss that you can claim to lower your income is the lesser of $3,000 ($1,500 if married filing separately) or your total net loss shown on line 16 of Schedule D (Form 1040), Capital Gains and Losses. That means you cannot simply write off the entire shortfall in the year you realize it; the deduction stops at whichever of those two figures is smaller.
According to Internal Revenue Service, for example, a loss disallowed in 2024 under Rule 1 will not be allowed in 2025, unless the substantially identical stock or securities (which caused the loss to be disallowed in 2024) were disposed of during 2025.
The practical takeaway for a landlord or investor is to track two separate numbers each year. First, calculate your net loss on Schedule D to see where you stand against the $3,000 (or $1,500) ceiling. Second, keep a list of any loss disallowed in 2024 under Rule 1 so you can check whether the substantially identical stock or securities were disposed of during 2025.
State specific reporting requirements for capital assets
California has its own reporting duty that runs alongside your federal filing. According to California Franchise Tax Board, all taxpayers must report gains and losses from the sale or exchange of capital assets. That means a rental property sale or an investment liquidation is not something you can leave off your state return even if you already reported it federally.
The tax treatment in California is different from the federal rate structure. According to California Franchise Tax Board, all capital gains are taxed as ordinary income. There is no preferential capital gains rate at the state level, and according to California Franchise Tax Board, California does not have a lower rate for capital gains. Plan your state tax liability using your ordinary income brackets rather than the federal capital gains schedule.
When your state treatment diverges from your federal treatment, you need a separate form. According to California Franchise Tax Board, if you have a difference in the treatment of federal and state capital gains, file California Capital Gain or Loss Schedule D (540). Compare your federal Schedule D against the state version before you submit.
Pull your federal Schedule D and your California Schedule D (540) side by side, and check each line for treatment differences before you file your state return. Today, sort each sale onto Form 8949, then read Name control rules for 2 e-file problems and E-file rejection errors: 7 troubleshooting checkpoints before you e-file.
FAQ: How to report capital gains and losses on tax returns
What is the maximum amount of capital loss I can deduct against my income?
If your capital losses exceed your capital gains, the amount of the excess loss you can claim to lower your income is the lesser of $3,000 ($1,500 if married filing separately) or your total net loss shown on line 16 of Schedule D (Form 1040), Capital Gains and Losses, according to Internal Revenue Service.
How does the wash sale rule affect my ability to deduct a loss?
Internal Revenue Service rules prohibit you from deducting losses related to wash sales, according to U.S. Securities and Exchange Commission. When a wash sale occurs, the loss is not simply lost; it gets added to the cost basis of the repurchased stock, which means you defer the deduction until you eventually sell that new position.
What is the tax rate on most net capital gain for 2025?
For taxable years beginning in 2025, the tax rate on most net capital gain is no higher than 15% for most individuals, according to Internal Revenue Service. Note that this is a cap, not a flat rate — depending on your taxable income, some or all of your net capital gain may be taxed at 0%.
Do I need to report capital gains on my California state return?
Yes. California does not offer a preferential rate for these gains; they are taxed as ordinary income on your state return, so you will need to complete the state version of Schedule D alongside your federal filing.
How do I calculate the basis for an asset I received as a gift?
Generally, an asset's basis is its cost to the owner, but if you received the asset as a gift or inheritance, refer to Publication 551, Basis of Assets for information about your basis, according to Internal Revenue Service.