Step-Up in Basis

Quick Definition

A step-up in basis is a tax provision that resets the cost basis of an inherited asset to its fair market value on the date the original owner dies. This means all the unrealized capital gains that accumulated during the original owner's lifetime are erased for tax purposes, and the heir starts with a clean basis equal to the asset's current value.

What It Means

When someone buys a stock, a house, or any investment, the purchase price becomes their cost basis. If they sell the asset later for more than that price, they owe capital gains tax on the difference between the sale price and the cost basis. Over decades, an asset can appreciate enormously, creating a large unrealized gain and a significant tax bill if sold.

The step-up in basis rule changes everything when an asset is inherited. Instead of inheriting the original owner's low cost basis, the heir receives a new cost basis equal to the fair market value of the asset on the date of death. All the appreciation that happened during the original owner's life is never taxed. The heir could sell the asset the next day and owe zero capital gains tax (assuming the value did not change between the death date and the sale date).

This provision is one of the most significant tax benefits in the U.S. tax code for families with appreciating assets. It applies to stocks, bonds, real estate, mutual funds, and most other capital assets passed through inheritance. It does not apply to assets gifted during the owner's lifetime (gifts retain the original cost basis, known as a carryover basis) or to retirement accounts like IRAs and 401(k)s (which have their own tax rules).

How It Works

The Basic Mechanism

1. Original owner buys an asset: The purchase price becomes the cost basis
2. Asset appreciates over time: The difference between current value and cost basis is the unrealized capital gain
3. Original owner dies: The asset passes to heirs through the estate
4. Basis is stepped up: The heir's new cost basis equals the fair market value on the date of death
5. Heir sells the asset: Capital gains tax is calculated only on appreciation after the date of death

Step-Up vs. Carryover Basis

This is why holding appreciated assets until death can be far more tax-efficient than selling them during your lifetime or gifting them while alive.

Community Property States

In community property states, the step-up can be even more powerful. When one spouse dies, both spouses' halves of community property get a step-up in basis, not just the deceased spouse's half. The nine community property states are Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin.

The Alternative: Date of Death vs. Alternate Valuation Date

The executor of the estate can choose between two valuation dates:

• Date of death: Fair market value on the day the person died (default)
• Alternate valuation date: Fair market value six months after the date of death (available only if elected for the entire estate and if it reduces the estate tax value)

The alternate valuation date is useful when asset values have declined since the date of death, giving the heir a lower basis (which is actually better for the heir because it means less gain when they sell). However, it can only be used if it reduces the total estate value for estate tax purposes.

Real-World Examples

Example 1: Stock Portfolio Inherited

Robert bought 1,000 shares of Apple stock in 2005 for $50 per share (total cost basis: $50,000). He died in 2026 when Apple was trading at $250 per share. His daughter Sarah inherits the shares.

If Sarah sells the shares immediately at $250, she owes zero capital gains tax. If she holds them and sells later at $280, she pays capital gains tax only on the $30 per share appreciation that occurred after Robert's death.

Example 2: Rental Property Inherited

Maria bought a rental house in 1990 for $120,000. She made $30,000 in capital improvements over the years, bringing her adjusted basis to $150,000. She died in 2026 when the house was worth $650,000. Her son inherits the property.

If Maria had sold the property a month before her death, she would have owed approximately $75,000 in long-term capital gains tax. By holding it until death, the entire $500,000 gain is erased for tax purposes, and her son inherits the property with a $650,000 basis.

Example 3: Community Property Step-Up

John and Mary live in California (a community property state). They jointly bought stock for $100,000 years ago. John dies when the stock is worth $800,000.

In a community property state, Mary gets a full step-up on the entire $800,000 value. In a separate property state, only John's half ($400,000) gets stepped up, so Mary's basis would be $450,000 ($50,000 original basis on her half plus $400,000 stepped-up basis on John's half).

What Does NOT Get a Step-Up in Basis

Not all assets receive a step-up in basis when inherited. The major exceptions are:

Retirement accounts are the biggest exception. When you inherit a traditional IRA or 401(k), the balance does not get a step-up. The heir pays ordinary income tax on withdrawals because the original contributions were made pre-tax and the tax was never paid. These assets are classified as Income in Respect of a Decedent (IRD).

Estate Tax vs. Step-Up in Basis

The step-up in basis and the estate tax are two separate systems that sometimes overlap. For 2026, the federal estate tax exemption is $15 million per individual ($30 million per married couple). This means only estates exceeding $15 million owe any federal estate tax.

For most families, the estate is well below the exemption, so no estate tax is owed, and the heirs still get the full step-up in basis. This is a double benefit: no estate tax and no capital gains tax on lifetime appreciation.

For very large estates above the exemption, the estate may owe estate tax (up to 40%) on the excess, and the heirs still get a step-up in basis. In this case, the stepped-up basis is the value used for estate tax purposes, so the same valuation serves both functions.

Key Points to Remember

• A step-up in basis resets the cost basis of inherited assets to their fair market value on the date of death
• All unrealized capital gains during the original owner's lifetime are erased and never taxed
• The step-up applies to capital assets (stocks, real estate, mutual funds) but not to tax-deferred retirement accounts (IRAs, 401(k)s)
• In community property states, both spouses' halves of community property get a step-up when one spouse dies
• The 2026 federal estate tax exemption is $15 million per individual, meaning most estates owe no estate tax but still receive the step-up benefit
• Assets gifted during the owner's lifetime do not get a step-up; they retain the original cost basis (carryover basis)
• The executor can choose the alternate valuation date (six months after death) if it reduces the estate tax value

Common Mistakes to Avoid

• Selling appreciated assets before death instead of holding them: If you have large unrealized gains and do not need the money, holding the asset until death passes it to heirs with a stepped-up basis, erasing the gain. Selling during your lifetime triggers capital gains tax.
• Gifting appreciated assets instead of bequeathing them: A gift during your lifetime carries over your original cost basis. The recipient will owe capital gains tax on all the appreciation when they sell. Bequeathing the same asset at death gives the recipient a stepped-up basis.
• Assuming retirement accounts get a step-up: Traditional IRAs, 401(k)s, and annuities do not receive a step-up in basis. Heirs pay ordinary income tax on withdrawals. Only Roth IRA distributions remain tax-free for heirs.
• Not documenting the date-of-death value: Heirs need to establish the fair market value at the date of death for their new basis. For publicly traded securities, this is straightforward. For real estate or private business interests, obtain a professional appraisal. Without documentation, the IRS may challenge the claimed basis.
• Overlooking the community property advantage: In community property states, couples can get a full step-up on jointly held assets when one spouse dies. This can save hundreds of thousands of dollars in capital gains tax compared to separate property states. Consult an estate planning attorney to ensure assets are properly titled.
• Forgetting that the step-up works both ways: If an asset has declined in value since purchase, the date-of-death fair market value may be lower than the original cost basis. This is a step-down in basis, and the heir's basis is the lower value. The original loss is never deductible.

Related Concepts

The step-up in basis is a key component of estate planning and interacts with several other tax concepts. The capital gains tax that would have been owed on lifetime appreciation is erased by the step-up, which is separate from the estate tax that applies to very large estates (above $15 million in 2026). The stepped-up basis is reported on the heir's Form 1040 when they eventually sell the inherited asset, and the calculation flows through their adjusted gross income. A trust can be used to manage how assets pass to heirs, though the step-up rules depend on trust structure. Naming a beneficiary on retirement accounts does not provide a step-up because IRAs and 401(k)s are classified as IRD. For practical guidance, read our post on what to do with an inheritance and our capital gains tax explained guide.

Frequently Asked Questions

Q: Does the step-up in basis apply to a primary residence? A: Yes. A personal residence is a capital asset, so it receives a step-up in basis when inherited. If your parents bought their home for $80,000 and it was worth $500,000 when they died, your basis as the heir is $500,000. If you sell it for $510,000, you owe capital gains tax only on the $10,000 of appreciation after their death.

Q: What is the difference between a step-up in basis and the estate tax exemption? A: They are separate provisions. The step-up in basis erases unrealized capital gains for the heir. The estate tax exemption ($15 million per individual in 2026) determines whether the estate itself owes tax. Most estates are below the exemption, so no estate tax is owed, and heirs still get the full step-up. For estates above the exemption, estate tax may be owed on the excess, and heirs still get the stepped-up basis.

Q: Do I get a step-up in basis on an inherited IRA? A: No. Inherited traditional IRAs, 401(k)s, and other tax-deferred retirement accounts do not receive a step-up in basis. These accounts are classified as Income in Respect of a Decedent (IRD), meaning the tax that was deferred during the original owner's life is still owed when the heir withdraws the money. Roth IRAs do not need a step-up because qualified distributions are already tax-free.

Q: How do I prove the stepped-up basis if the IRS questions it? A: For publicly traded stocks and bonds, the date-of-death price is well-documented through brokerage records. For real estate, obtain a professional appraisal dated as close to the date of death as possible. For private business interests, a qualified business valuation may be needed. Keep all appraisal reports, brokerage statements, and estate tax returns (Form 706) as documentation.

Q: Can I get a step-up in basis on assets I gift to my children while I am alive? A: No. Assets gifted during your lifetime retain your original cost basis (carryover basis). Only assets transferred at death through inheritance receive a step-up. If you want your children to benefit from the step-up, you generally need to hold the assets until death rather than gifting them during your lifetime. However, gifting may still make sense for other reasons, such as reducing your estate tax exposure or helping children while you are alive.