What Is Cost Basis? How It Works, Calculation, Taxation, and Example (2024)

What Is Cost Basis?

Calculating the total cost basis is critical to understanding whether an investment is profitable and what its tax treatment will be.If investors want to know whether an investment has provided gains, and what they will owe in terms of tax on those gains, they need to keep track of the investment's performance between purchase and sale.

Key Takeaways

Cost basis is the original value or purchase price of an asset or investment for tax purposes.
Cost basis is used to calculate capital gains tax, which is levied on the difference between the asset's cost basis and current market value.
Most brokerages offer cost basis tracking and report any necessary gains and losses to the IRS on Form 1099-B.
The general default method for determining cost basis by brokerages is First In, First Out (FIFO).

Understanding Cost Basis

Cost basis starts as the original cost of an asset for tax purposes, which is the first purchase price.But the initial purchase price is only one part of the overall cost of an investment. Over time, this cost basis may be adjusted for financial and corporate developments, such as stock splits, dividends, and return of capital distributions—the latter is common with certain investments, such as Master Limited Partnerships (MLPs).

The cost basis for capital assets like real estate can also be adjusted. This will be based on the price of any capital improvements or any casualty loss amounts.

Cost basis is used to determine the capital gains tax rate, which is equal to the difference between the asset's cost basis and the current market value. Of course, this rate is triggered when an asset is sold, or the gain or loss is realized. Tax basis still holds for unrealized gains or losses when securities are held but have not been officially sold. Taxing authorities will require a determination of the capital gains rate, which can be either short- or long-term.

Long-term capital gains have been held for over a year and are taxed at the capital gains rate. Short-term capital gains have been held for less than a year and are taxed as ordinary income.

The Internal Revenue Service (IRS) allows cost basis to be determined using the First In, First Out (FIFO) method (which is the default) or specific share identification. The latter allows the investor to identify which shares were sold. However, the designation must be made in advance to the brokerage—outlining which shares are being sold.

Tax Reporting Cost Basis

Brokerage firms are required to report the price paid for taxable securities to the IRS for most securities, which are reported using FIFO. Brokerages, however, are only required to report an asset sale to the IRS if the investment was made after:

Calculating Cost Basis

To reiterate, the cost basis of any investment is equal to the original purchase price of an asset. Every investment will start with this status, and if it ends up being the only purchase, determining the cost is merely the original purchase price. Note that it is allowable to include the cost of a trade, such as a stock-trade commission, which can also be used to reduce the eventual sales price.

Once an investor makes subsequent purchases, the need arises to track each purchase date and value. For tax purposes, the default method used by the IRS (and how most brokerages will report gains and losses) is FIFO. In other words, when an investor sells, the cost basis on the original purchase would first be used and would follow a progression through the purchase history.

Mutual fund investors have another option (besides FIFO and specific-share identification), which is the average cost basis.

For example, let's assume Leigh purchased 100 shares of XYZ for $20 per share in June and then makes an additional purchase of 50 XYZ shares in September for $15 per share.

If she sold 120 shares, her cost basis using the FIFO method would be:

(100 x $20 per share) + (20 x $15 per share) = $2,300

The average cost method may also be applicable and represents the total dollar amount of shares purchased, divided by the total number of shares purchased. If Leigh sold 120 shares, her average cost basis would be:

120 x [(100 x $20 per share) + (50 x $15 per share)]/ 150 = $2,200

There are also differences among securities, but the basic concept of the purchase price is applied. Typically, most examples cover stocks. However, bonds are somewhat unique in that the purchase price above or below par must be amortized until maturity.

For mutual funds, there might be taxable events each year if the funds are held in taxable (non-qualified) accounts, such as distributions. A custodian will track all amounts, or a mutual fund firm will provide guidance.

Why Is Cost Basis Important?

Cost basis primarily needs to be tracked for tax purposes. Without this requirement, it is likely that most investors would not bother keeping such detailed records.

Capital gains can be taxed at ordinary income rates in the case of short-term capital gains, so it pays to minimize them if at all possible. Holding securities for longer than one year qualifies the investment as a long-term investment, which carries a much lower tax rate than ordinary income rates and decreases based on income levels.

In addition to the IRS requirement to report capital gains, it's wise to track how an investment has performed over time. Savvy investors know what they have paid for a security and how much in taxes they have to pay if they sell it.

Tracking gains and losses over time also serves as a scorecard for investors and lets them know if their trading strategies are generating profits or losses. A steady string of losses may indicate a need to reevaluate the investment strategy.

Special Considerations

Calculating the cost basis gets more complicated as a result of corporate actions. They include items such as adjusting for stock splits and accounting for special dividends, bankruptcies, and capital distributions, as well as merger and acquisition activity and corporate spinoffs. A stock split, such as a two-for-one split, in which a company issues an additional share for every share an investor owns, doesn’t change the overall cost basis. It does mean the cost per share becomes divided by two, or whatever the share exchange ratio ends up being following the split.

Determining the impact of corporate actions isn’t overly complicated, but it can require sleuthing skills such as locating a CCH manual, which provides accounting and audit information, from a local library or heading to the investor relations section of a company’s website. These sources usually provide plenty of detail on activity or spinoffs.

Dividends

To calculate the equity cost basis for a non-dividend-paying stock, you add the purchase price per share plus fees per share. Reinvesting dividends increases the cost basis of the holding because dividends are used to buy more shares.

For example, let's say an investor bought 10 shares of ABC company for a total investment of $1,000 plus a $10 trading fee. The investor receives dividends of $200 in yearone and $400 in year two. The cost basis would be $1,610 ($1,000 + $10 fee + $600 in dividends).If the investor sold the stock in yearthree for $2,000, the taxable gain would be $390.

One reason investors need to include reinvested dividends into the cost basis total is because dividends are taxed in the year received. If the dividends received are not included in the cost basis, the investor will pay taxes on them twice.For instance, in the above example, if dividendswere excluded, the cost basis would be $1,010 ($1,000 + $10 fee). As a result, the taxable gain would be $990 ($2,000 - $1,010 cost basis) versus $390 had the dividend income been included in the cost basis.

In other words, when selling an investment, investors pay taxes on the capital gains based on the selling price and the cost basis. However, dividends get taxed as income in the year they're paid to the investor, regardless of whether the dividends were reinvested or paid out as cash.

Mergers

When a company you own is acquired by another company, the acquiring company will issue stock, cash, or a combination of both to complete the purchase. Payouts for cash will result in having to realize a portion as a gain and pay taxes on it.

The issuance of shares will likely keep capital gains or losses as unrealized, but it will be necessary to track the new cost. Companies guide the percentages and breakdowns. The same rules also apply when a company spins out a division into its own new company. Some of the tax costs will go with the new firm, and it will be necessary for the investor to determine the percentage, which the company will provide.

For example, if XYZ company buys ABC company and issues two shares for every one share previously owned, thenthe investor referred to in the previous examplenow owns 20 shares of XYZ company.Companies need to file Form S-4 with the Securities and Exchange Commission (SEC), which outlines the merger agreement and helps investors determine the new cost basis.

Bankruptcies

Bankruptcy situations are even more complicated.When companies declare bankruptcy, the impact on shares varies. Declaring bankruptcy does not always indicate that shares are worthless. If a company declares Chapter 7, then the company ceases to exist, and the shares are worthless.

However, if a company declares Chapter 11, the stock may still trade on an exchange or over the counter (OTC) and still retain some value. Therefore the initial cost basis calculations apply.OTC is a broker-dealer network that trades securities that are not listed on a formal exchange.

Ifthe bondholder of a company emerging from Chapter 11 isgiven common stock in exchange for some of the bonds held before declaring bankruptcy, the cost basis becomes more complicated.The cost basis would typically be considered the fair market value of the common stock on the effective date; this value is laid out in Chapter 11 emergence plans.

Stock Splits

Thankfully, not all corporate actions complicate cost basis calculations; declaring a stock split is one such action. If a company declares a 2-for-1 split, instead of owning10 shares of ABC company,an investorwould own 20 shares. However, the initial cost of $1,000 stays the same, so the 20 shares would have a price of $50 instead of $100 per share.

Inherited Stocks and Gifts

Non-corporate actions such as receiving a stock gift or inheritance can also impact cost basis. Calculating the cost basis for inherited stock is done by taking the fair market value (FMV) on the date of the benefactor's death.

Conversely, a gifted stock is more complicated. Ifan investorsells the stock, the cost basis becomes the purchase price on the date the gifter bought the stock, unless the price is lower on the date of the gift.If this is the case, the tax cost can be reduced, since the stock has suffered a loss in value.

Tracking Cost Basis

Several methods can help minimize the paperwork and time needed to track cost basis. Companies offer dividend reinvestment plans (DRIPs) that allow dividends to be used to buy additional stock in the firm. If possible, keep these programs in a qualified account where capital gains and losses don’t need to be tracked. Every new DRIP purchase results in a new tax lot. The same goes for automatic reinvestment programs, such as investing $1,000 every month from a checking account. New purchases always mean new tax lots.

The easiest way to track and calculate cost basis is through brokerage firms.Whether an investor has an online or traditional brokerage account, firms have very sophisticated systemsthat maintain records of transactions and corporate actions related to stocks.

However, it's always wise for investors to maintain their records by self-tracking to ensure the accuracy of the brokerage firm's reports.Self-tracking will also alleviate any future problems if investors switch firms, gift stock, or leave stocks to a beneficiary as an inheritance.

For stocks that have been held over many years outside of a brokerage firm, investors may need to look up historical prices, found on the internet, to calculate the cost basis.

For investors who self-track stocks, financial software such as Intuit's Quicken, Microsoft Money, or Microsoft Excel, can organize the data.Lastly, websites such as GainsKeeper or Netbasis, are available to provide cost basis and other reporting services for investors.All of these resources make it easier to track and maintain accurate records.

What Is First In, First Out (FIFO) for Taxes?

First In, First Out, commonly known as FIFO, is an asset-management and valuation method in which assets produced or acquired first are sold, used, or disposed of first. For tax purposes, FIFO assumes that assets with the oldest costs are included in the income statement's cost of goods sold (COGS). The remaining inventory assets are matched to the assets most recently purchased or produced.

What Is Capital Gains Tax?

Capital gains tax is the tax levied on profits from the sale of capital assets. These are significant assets that can realize a profit when they are sold, such as investments, art, or real estate. Gains from the sale of these assets are long-term if the asset was held for more than a year before it was sold. Long-term capital gains are taxed at the capital gains rate, which is 0%, 15%, or 20% depending on your income bracket. Gains for capital assets that were held for less than a year are considered short-term capital gains and are taxed at your ordinary income rate.

What Are Dividends?

A dividend is the distribution of a company's earnings to its shareholders and is determined by the company'sboard of directors. Dividends are often distributed quarterly and may be paid out as cash or as reinvestment inadditional stock.

The Bottom Line

Cost basis is the original value or purchase price of an asset or investment for tax purposes. It is used to calculate capital gains or losses, which is the difference between the selling and purchase prices of capital assets. Tracking cost basis is required for tax purposes. It is also key if investors want to determine their investments' success.