How to Calculate Step-Up in Basis Tax Savings on Inherited Assets

What the Step-Up in Basis Rule Actually Does

The IRS resets the cost basis of inherited assets to their fair market value on the date of the decedent's death. This is Internal Revenue Code Section 1014. It is one of the most valuable provisions in the tax code for wealth transfer.

Your parent bought 1,000 shares of Apple stock in 2001 for $1.00 per share. Total original basis: $1,000. Those shares are worth $185,000 on the date of death. Your inherited basis is $185,000, not $1,000. If you sell immediately, your taxable gain is zero.

Without this rule, the embedded gain of $184,000 would generate a federal long-term capital gains tax bill of $27,600 at the 15% rate, or $36,800 at the 20% rate for high earners. The step-up eliminates that liability entirely.

This is not a loophole. It is the law, and it applies to a broad range of asset classes.

Which Assets Qualify for the Step-Up

The rule covers assets that pass through a decedent's taxable estate. That includes:

• Individually owned stocks and mutual funds held in taxable brokerage accounts
• Real property, including primary residences, rental properties, and land
• Business interests such as sole proprietorships, partnership interests, and S-corporation shares
• Collectibles, art, jewelry, and precious metals
• Bonds held in taxable accounts

The rule does not apply to assets inside tax-deferred retirement accounts. IRAs and 401(k)s pass to beneficiaries as ordinary income, not capital gains. The basis rules are entirely different there.

It also does not apply to assets given as gifts during the donor's lifetime. Gifted assets carry the donor's original basis forward, which is the carryover basis rule. This distinction matters enormously in estate planning.

Community Property States Add a Bonus

In the nine community property states, including California, Texas, and Arizona, surviving spouses receive a double step-up. Both halves of community property get revalued at death, even though only the decedent's half passes through the estate. A couple that bought a rental property in 1985 for $120,000, now worth $900,000, ends up with a $900,000 basis for both spouses. The unrealized gain of $780,000 disappears entirely.

How to Calculate the Stepped-Up Basis: Step by Step

The calculation has four components. Get all four right before you file.

Step 1: Identify the valuation date. The standard valuation date is the date of death. Executors of larger estates may elect an alternate valuation date six months after death if the total estate value has declined. This election applies to the entire estate, not individual assets, and requires filing Form 706.

Step 2: Determine fair market value on that date. Fair market value is the price a willing buyer would pay a willing seller, with neither under compulsion to act. For publicly traded securities, this is the average of the high and low trading prices on the date of death. For real estate and private assets, a qualified appraisal is required.

Step 3: Document the valuation. For securities, a brokerage statement showing the date-of-death price is sufficient. For real estate, obtain an IRS-qualified appraisal from a certified appraiser. For business interests, a business valuation from a credentialed professional such as a Certified Valuation Analyst is the standard.

Step 4: Use the stepped-up figure as your cost basis going forward. When you sell the asset, subtract the stepped-up basis from the sale price to determine your taxable gain. Gains on assets held more than one year after inheritance qualify for long-term capital gains rates regardless of how long the decedent held them.

Worked Example 1: Inherited Stock Portfolio

Margaret inherits a taxable brokerage account from her father. The account holds three positions:

Total original basis: $62,350. Total stepped-up basis: $411,900.

Margaret sells all three positions six months after inheriting them for $427,500 combined.

Using the stepped-up basis, her taxable gain is $427,500 minus $411,900, which equals $15,600. At the 15% long-term rate, she owes $2,340 in federal capital gains tax.

Had she incorrectly used the original basis of $62,350, her taxable gain would have been $365,150. At 15%, that produces a tax bill of $54,772.

The step-up saves Margaret $52,432 in federal tax alone. State taxes on capital gains would add to that gap.

Worked Example 2: Inherited Rental Property

David inherits a rental property in Denver from his aunt. The property details:

• Original purchase price (1994): $148,000
• Depreciation claimed over 30 years: $43,636
• Adjusted basis at death: $104,364
• Appraised fair market value at date of death: $740,000

Without the step-up, David's basis would be $104,364. Selling at $740,000 produces a gain of $635,636. A portion of that gain, $43,636, represents depreciation recapture taxed at 25%. The remaining $592,000 qualifies for long-term capital gains rates. At the 20% rate for a high-income taxpayer, plus the 3.8% net investment income tax, his combined federal rate on the capital gain portion reaches 23.8%.

Tax on depreciation recapture: $43,636 times 25% equals $10,909. Tax on long-term gain: $592,000 times 23.8% equals $140,896. Total federal tax without step-up: $151,805.

With the step-up, David's new basis is $740,000. He sells immediately at that price. His taxable gain is zero. Depreciation recapture does not apply because the stepped-up basis wipes out all prior depreciation for purposes of calculating gain on sale.

The step-up saves David $151,805 in federal tax on a single transaction.

Partial Interests and Joint Ownership Complicate the Math

Not every inherited asset passes with a full step-up. The fraction of the asset included in the decedent's taxable estate determines how much basis gets reset.

Consider a property held in joint tenancy with right of survivorship between two unrelated individuals. Only the decedent's 50% interest receives the step-up. If the property was worth $600,000 at death, the surviving owner's basis increases by $300,000, not $600,000.

For assets held in revocable living trusts, the step-up still applies because those assets remain in the taxable estate. Irrevocable trusts vary by structure. Assets in certain irrevocable trusts may not receive a step-up if they are not included in the gross estate under IRC Section 2036 or 2038.

QTIP trusts, commonly used in second marriages, typically do produce a step-up on the surviving spouse's death because the assets are included in the surviving spouse's taxable estate.

Get the trust documents and confirm inclusion in the taxable estate before assuming a step-up applies.

The Alternate Valuation Date Election

Executors of taxable estates can elect to value assets six months after the date of death rather than on the date itself. This election requires that both the gross estate value and the estate tax liability are lower on that alternate date. You cannot use it to cherry-pick favorable valuations for individual assets.

In a declining market, the alternate valuation date can reduce estate tax on large estates. But it also reduces the stepped-up basis, which may increase capital gains tax for beneficiaries later. The executor must weigh estate tax savings against the long-term capital gains tax cost to heirs.

For estates below the federal exemption threshold, currently $13.61 million per individual in 2024, the alternate valuation date election is almost never beneficial because there is no estate tax to offset.

Documentation: What the IRS Requires

The IRS can audit basis claims years after a sale. Proper documentation is non-negotiable.

For publicly traded securities, print and retain the brokerage statement showing closing prices on the date of death. Most major custodians provide stepped-up basis information directly to beneficiaries.

For real estate, retain the qualified appraisal, the appraiser's credentials, comparable sales data used in the appraisal, and the title transfer documents. Appraisals should be ordered within a reasonable period after the date of death, ideally within six months.

For business interests, retain the full valuation report, the valuation analyst's credentials, and the methodology used. A single-page estimate is not sufficient. The IRS scrutinizes estate valuations of closely held businesses carefully.

Retain all records for at least three years after the tax return on which you report the sale. Longer retention is prudent for high-value assets.

Run the Numbers Before You Sell Anything

The step-up in basis calculation directly determines your tax bill on every inherited asset sale. One wrong input, specifically using the original cost instead of the date-of-death value, produces a tax overpayment that the IRS has no obligation to correct for you.

Before you sell an inherited stock, property, or business interest, calculate the stepped-up basis and the resulting gain with precision. The CalcMoney income tax calculator lets you input your specific basis, sale price, and income level to produce an accurate federal capital gains tax estimate in under two minutes.

The difference between the original basis and the stepped-up basis is real money. In the examples above, that difference ranged from $52,432 to $151,805 on single transactions. Run the calculation before any sale closes.

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