A realized gain is the profit you lock in when you sell an investment or other capital asset for more than you paid for it. Until the sale, any increase in value is a paper profit with no tax consequence. Once you sell, the difference between your net proceeds and your cost basis becomes taxable income, reported on Form 8949 and Schedule D and taxed either at ordinary rates or at the lower long-term capital gains rates, depending on how long you held the asset.1Internal Revenue Service. Instructions for Form 8949 (2025)
What Makes a Gain “Realized”
Buy 100 shares at $50 and watch the price rise to $75, and you have a $2,500 paper profit. Nothing is owed and nothing is reported, because the gain is unrealized. You still own the shares.
The gain becomes realized when you dispose of the asset. Disposition covers more than a straightforward sale; it includes exchanges, gifts, and certain other transfers.2Legal Information Institute. 26 USC 904(f)(3) – Definition: Disposition Selling those 100 shares at $75 turns the $2,500 paper profit into a realized gain that has to appear on your tax return. Because you choose when to sell, you also choose when the tax hits.
How to Calculate the Gain
The formula is straightforward: net sale proceeds minus your adjusted cost basis. Net proceeds are the sale price less any transaction costs such as brokerage fees. Cost basis starts with what you paid, including commissions, and gets adjusted over time for events like reinvested dividends (which add to basis) and return-of-capital distributions (which reduce it).
Sell shares for $10,000, pay $50 in fees, with an adjusted basis of $7,000, and your realized gain is $2,950. If the basis had been $11,000 instead, you’d have a $1,050 realized loss. Both get reported.
Which Shares Did You Sell?
If you bought the same stock or fund at different prices over time and are now selling only part of the position, you need a method for identifying which shares went out the door. Without an election, the IRS defaults to first-in, first-out, meaning your oldest shares are treated as sold first.3Internal Revenue Service. Stocks (Options, Splits, Traders) 3 Since the earliest shares often have the lowest basis, FIFO typically produces the largest taxable gain.
Specific identification lets you pick which lots to sell. Choosing high-basis shares shrinks the realized gain. The identification has to happen before the trade settles, and your broker needs a record of the selection. Mutual fund investors can instead elect the average cost method, which blends all share prices into one per-share basis and has to be applied consistently to that fund.
Brokers report proceeds and basis on Form 1099-B for covered securities, but basis accuracy is ultimately yours to prove. Older, non-covered holdings may show incomplete basis on the 1099-B, and you’ll need your own records to fill the gap.1Internal Revenue Service. Instructions for Form 8949 (2025)
How Realized Gains Are Taxed
Two things drive the rate: how long you held the asset and how much other taxable income you have. The dividing line for holding period is one year, counted from the day after you acquired the asset through the day you sold it.4Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Short-Term Gains
Assets held for one year or less produce short-term gains, taxed at your ordinary income rate. For 2026, the top ordinary rate is 37%, applying to single filers with taxable income above $640,600 and joint filers above $768,700.5Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 A large short-term gain can also push you into a higher bracket, so the effective rate on the gain can exceed your usual rate.
Long-Term Gains
Hold for more than a year and the gain qualifies for the preferential rates of 0%, 15%, or 20%. For 2026, the 0% rate applies up to $49,450 of taxable income for single filers and $98,900 for joint filers; the 15% rate applies above those ceilings up to $545,500 (single) or $613,700 (joint); the 20% rate applies above those upper thresholds.6Internal Revenue Service. Rev. Proc. 2025-32
The 0% bracket is worth planning around. If your total taxable income stays under the threshold, you can sell long-term holdings and owe no federal tax on the gain. Even filling part of the 0% bracket with realized gains can meaningfully cut the bill.
Higher Rates for Collectibles and Depreciation
Two categories of long-term gains face higher maximums. Collectibles like art, coins, and precious metals are taxed at a maximum 28% rate. Gains on depreciable real estate attributable to prior depreciation deductions are taxed at a maximum 25% rate.4Internal Revenue Service. Topic No. 409, Capital Gains and Losses Sell a rental property at a profit and the portion of the gain equal to the depreciation you claimed is taxed at that 25% rate before the standard long-term rates apply to any remaining gain.
The 3.8% Net Investment Income Tax
Higher earners owe an additional 3.8% surtax on net investment income, which includes realized capital gains. It applies to the lesser of your net investment income or the amount by which your modified adjusted gross income exceeds $200,000 (single), $250,000 (married filing jointly), or $125,000 (married filing separately).7Internal Revenue Service. Topic No. 559, Net Investment Income Tax These thresholds aren’t indexed for inflation. Combined with the 20% long-term rate, the top effective federal rate on long-term gains is 23.8%.
Using Losses to Reduce the Tax
Realized losses cut the tax on your gains directly. On Schedule D, short-term gains are first netted against short-term losses and long-term against long-term. If one category shows a net gain and the other a net loss, those two results are then netted against each other.1Internal Revenue Service. Instructions for Form 8949 (2025)
If your total losses exceed your total gains, you can deduct up to $3,000 of the excess against ordinary income ($1,500 if married filing separately).8Office of the Law Revision Counsel. 26 USC 1211 – Limitation on Capital Losses Any remainder carries forward to future years, keeping its short-term or long-term character, and doesn’t expire.9Office of the Law Revision Counsel. 26 USC 1212 – Capital Loss Carrybacks and Carryovers
The Wash Sale Trap
You can’t sell at a loss and immediately buy the same security back. If you acquire a substantially identical security within 30 days before or after the loss sale, the loss is disallowed.10Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities The disallowed loss is added to the basis of the replacement shares, so the benefit is deferred rather than lost. The rule also reaches contracts and options on the same security.
Tax-loss harvesting works around this by moving into a different but similar investment, not by rebuying the exact ticker within the 61-day window (30 days before through 30 days after).
Special Cases to Know About
Selling Your Home
A primary residence gets its own exclusion. Single filers can exclude up to $250,000 of gain, and joint filers up to $500,000.11Internal Revenue Service. Topic No. 701, Sale of Your Home You must have owned and used the home as your main residence for at least two of the five years before the sale, and you generally can’t have claimed the exclusion on another sale within the previous two years. Any gain above the exclusion is a taxable realized gain, reported on Schedule D and eligible for the long-term rates.
Inherited and Gifted Assets
Inherited assets get a step-up in basis to the fair market value on the date the original owner died.12Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent Appreciation during the decedent’s lifetime is never taxed, and the holding period is automatically long-term regardless of when the decedent bought the asset.
Gifted assets are different. You generally inherit the donor’s basis. If the donor’s basis is higher than the fair market value on the gift date, a split-basis rule applies: donor’s basis for calculating a gain, lower fair market value for calculating a loss, and no gain or loss at all if you sell somewhere between the two.13Office of the Law Revision Counsel. 26 USC 1015 – Basis of Property Acquired by Gifts and Transfers in Trust
Reporting the Gain
Every realized capital gain or loss goes on Form 8949, one line per transaction: description, date acquired, date sold, proceeds, and basis. Part I is for short-term, Part II for long-term.14Internal Revenue Service. About Form 8949, Sales and Other Dispositions of Capital Assets The totals flow to Schedule D, where the netting happens, the $3,000 loss cap is applied if relevant, and any carryforward is calculated.1Internal Revenue Service. Instructions for Form 8949 (2025)
If your only capital gains come from mutual fund or REIT distributions on Form 1099-DIV and you have no losses to report, you may be able to skip Form 8949 and report directly on Schedule D. Any actual sale of stock, bonds, or crypto requires the full Form 8949. Brokers file the same information with the IRS, and mismatches between your return and their 1099-B are a common trigger for automated notices.
Don’t Forget the Estimated Payment
Realize a large gain in the middle of the year and wages withholding probably won’t cover it. The IRS expects estimated tax payments when you’ll owe at least $1,000 after withholding and credits and your withholding won’t cover 90% of your current-year tax (or 100% of last year’s tax, or 110% if your prior-year adjusted gross income exceeded $150,000).15Internal Revenue Service. Large Gains, Lump Sum Distributions, Etc.
Quarterly payments are generally due April 15, June 15, September 15, and January 15 of the following year. You can annualize your income and pay a larger amount in the quarter the gain occurred rather than spreading it evenly. Sell a big position in October and the payment is due by January 15; miss it and you owe an underpayment penalty that functions as interest.
State Tax
Federal is only part of the bill. Most states tax capital gains as ordinary income, with rates running from zero in states with no income tax to above 13% in the highest. A few states apply special treatment, such as excluding a portion of long-term gains or taxing gains only above a threshold. In the most expensive jurisdictions, the combined federal and state rate on a large long-term gain can approach 37%. Check your state’s rules before deciding when to sell, because a gain that looks manageable federally can carry a much larger total once state tax is added.