Step-Up in Basis
A tax provision under IRC Section 1014 that resets the cost basis of an inherited asset to its fair market value on the date of the decedent's death, eliminating any capital gains tax on appreciation that occurred during the deceased's lifetime.
The step-up in basis is one of the most significant wealth transfer benefits in the U.S. tax code, and for investors with highly appreciated assets, it can result in the permanent elimination of enormous capital gains tax liabilities across generations. When a person dies and leaves behind appreciated securities or other capital assets, the heir's tax basis in those assets is 'stepped up' to the fair market value on the date of death — not the original purchase price paid by the decedent.
For example, suppose a parent purchased stock for $10,000 decades ago and it has grown to $500,000 at the time of death. If the parent had sold the stock, they would have owed capital gains tax on $490,000 of gain. But because the heir receives the stock with a stepped-up basis of $500,000, selling it immediately after inheriting it generates zero capital gain. The $490,000 of embedded gain is permanently forgiven by the federal tax system.
The rule applies to assets included in the decedent's taxable estate under Section 1014 of the Internal Revenue Code. It covers stocks, bonds, real estate, and most other capital assets. However, assets held in IRAs and 401(k)s do not receive a step-up in basis because they are not 'capital gain' assets in the same sense — their value derives from pre-tax dollars and will be taxed as ordinary income when withdrawn by heirs.
For assets held in community property states, both halves of community property receive the step-up at death, even the surviving spouse's half — a significant benefit over the common law property regime used in most states, where only the decedent's half is stepped up.
The step-up in basis shapes long-term estate planning strategy. Investors with large unrealized gains often choose to hold appreciated assets until death rather than selling during their lifetime, knowing that the gain will escape income taxation entirely. Conversely, gifting appreciated assets during life transfers the donor's original basis to the recipient (the 'carryover basis' rule), meaning the recipient will owe capital gains tax on the full appreciation if they sell the gifted asset.
Step-Up Example: A concrete numerical example illustrates the magnitude of this benefit. Suppose a retiree holds a position in a large-cap index fund purchased 30 years ago for $50,000 that is now worth $800,000. The embedded long-term gain is $750,000, which at the 20% federal rate plus 3.8% NIIT produces a potential federal tax of $178,500 — plus state income tax in many states. If the retiree holds the position until death and leaves it to an adult child, the heir's cost basis becomes $800,000. The heir can sell immediately for $800,000 and owe zero capital gains tax on the transaction. The $178,500+ of federal tax liability is permanently extinguished. For investors with concentrated, low-basis positions, this dynamic is the foundation of the 'die with it' portfolio strategy — holding appreciated assets and funding living expenses through other means rather than selling.
Estate Planning Implications: The step-up in basis interacts with estate tax in complex ways that require careful planning. For estates below the federal estate tax exemption ($13.99 million per individual in 2025), the step-up in basis is essentially a free benefit — heirs receive appreciated assets with no income tax on the accumulated gain and no estate tax on the value. For estates above the exemption, the estate tax reduces the value passed to heirs, but the step-up still benefits those heirs by eliminating the income tax layer. Estate planners often advise high-net-worth clients to prioritize retaining appreciated assets in the taxable estate (to receive the step-up) over gifting them during life (where carryover basis applies). This is particularly true for assets such as concentrated stock positions, real estate with large depreciation recapture, and low-basis index fund holdings accumulated over decades. Assets held in IRAs and 401(k)s receive no step-up and pass to heirs with their full pre-tax value intact — a consideration that can influence whether retirement accounts should be converted to Roth IRAs (which pass income-tax-free to heirs) or left as pre-tax accounts subject to ordinary income tax upon distribution.