Step-Up in Basis at Death: The Estate Planning Strategy That Eliminates Capital Gains for Your Heirs

Imagine your parents bought a beach cottage in 1985 for $90,000. Today, after four decades of appreciation, it is worth $1.2 million. If they sold it tomorrow, they would face a capital gains bill on more than $1 million of appreciation — federal long-term capital gains tax alone could exceed $200,000, plus state taxes and the 3.8% Net Investment Income Tax.

But if they hold that cottage until they pass away and leave it to you, something remarkable happens in the tax code. The cost basis "steps up" to fair market value on the date of death. Your basis becomes $1.2 million. If you sell shortly afterward for $1.2 million, you owe nothing in capital gains tax. The decades of appreciation that accumulated during your parents' lifetime simply vanish from the tax base.

This is the step-up in basis rule, and it is one of the most powerful — and most overlooked — tools in modern estate planning. It survived the One Big Beautiful Bill Act of 2025, applies to virtually all appreciated capital assets, and saves American families an estimated $72.5 billion per year in forgone federal tax revenue. Yet it is also one of the most misunderstood provisions in the tax code, with technical traps that can cost your heirs hundreds of thousands of dollars if handled incorrectly.

What the Step-Up in Basis Actually Does

Cost basis is the figure the IRS uses to calculate gain or loss on the sale of an asset. Under normal rules, your basis is what you paid for something, adjusted for improvements, depreciation, and a handful of other items. When you sell, your taxable gain equals the sale price minus your basis.

Section 1014 of the Internal Revenue Code carves out a special rule for property received from a decedent. Instead of inheriting the original owner's cost basis, the heir receives a basis equal to the fair market value of the property on the decedent's date of death. The pre-death appreciation effectively becomes tax-free for the heir.

A simple example makes this clear. Suppose your aunt bought 500 shares of a tech stock in 2005 at $20 per share, for a total cost of $10,000. By the time she passes away in 2026, those shares are worth $400 each, or $200,000 total. If she had sold them while alive, her taxable gain would have been $190,000. Instead, she leaves them to you. Your new basis is $200,000 — the date-of-death value. If you sell at $200,000 the next month, your taxable gain is zero.

This treatment applies whether the asset goes through probate, passes through a revocable living trust, transfers via a transfer-on-death registration, or passes by joint tenancy with rights of survivorship. The trigger is death, not the legal vehicle.

Why This Rule Matters More Than Ever in 2026

For most of the last two decades, the step-up in basis worked alongside the federal estate tax. Wealthy families paid estate tax on what they passed down, but their heirs got the basis adjustment as a partial offset. With the federal estate tax exemption now sitting at $15 million per individual and $30 million per married couple in 2026, fewer than 0.1% of estates owe any federal estate tax at all.

That changes the planning calculus dramatically. For nearly every American family, estate tax is no longer the central concern. Income tax planning — particularly capital gains tax planning — has taken its place. The step-up in basis is the single largest income tax break available to middle-class and upper-middle-class families, and it costs the federal government an estimated $72.5 billion in 2026 according to the Joint Committee on Taxation.

That number tells you something important. The step-up is not a niche provision for the ultra-wealthy. It is a mass-market tax benefit that touches almost every inheritance involving real estate, taxable brokerage accounts, or family business interests.

What Qualifies — and What Doesn't

The step-up applies to capital assets owned by the decedent at the time of death. The list of qualifying assets is broad:

• Real estate, including primary residences, vacation homes, and rental properties
• Stocks, bonds, mutual funds, and ETFs held in taxable brokerage accounts
• Collectibles, art, and precious metals
• Closely held business interests, including LLC and partnership interests
• Cryptocurrency held in personal wallets or taxable accounts

What does not qualify is just as important to know. Tax-deferred retirement accounts get no step-up because the assets inside have never been taxed in the first place. The list of non-qualifying assets includes:

• Traditional IRAs, 401(k)s, 403(b)s, and similar tax-deferred accounts
• Annuities and tax-deferred deferred compensation
• Items of "income in respect of a decedent" (IRD), such as accrued but unpaid bond interest, deferred stock option income, or final paychecks
• Roth IRAs technically receive a step-up in basis, but since qualified Roth withdrawals are already tax-free, the rule has no practical effect

This distinction is the source of one of the most common estate planning mistakes. Families sometimes accelerate withdrawals from a brokerage account during the parent's final years to "spend down" appreciated assets, while leaving IRAs untouched. The opposite is usually correct: spend the IRA, preserve the brokerage account for the step-up.

The Married Couple Wrinkle: Half Step-Up vs. Double Step-Up

When one spouse dies, the surviving spouse generally receives a step-up on the deceased spouse's share of jointly held property. In most states — known as common law or separate property states — that means a half step-up on jointly owned assets. Only the deceased spouse's 50% interest is revalued; the surviving spouse's half retains its original basis.

In community property states, the rules are dramatically more generous. The entire property — both halves — gets a step-up to fair market value at the first spouse's death. This is the so-called "double step-up." The nine community property states are Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin. Alaska, Florida, Kentucky, South Dakota, and Tennessee allow couples to opt into community property treatment through specially designed community property trusts, even though they are common law states by default.

For a couple in Texas who jointly bought a home for $100,000 that is now worth $1 million, the difference is stark. When the first spouse dies, the surviving spouse's basis becomes the full $1 million in Texas. In Pennsylvania, that same surviving spouse's basis becomes only $550,000 (half stepped up to $500,000 plus the unchanged $50,000 share). Selling the home for $1 million the following year produces zero taxable gain in Texas and a $450,000 taxable gain in Pennsylvania.

Couples with substantial appreciated assets who live in common law states should at least discuss community property trusts with an estate planning attorney. The savings can be enormous, and the compliance cost is modest by comparison.

The Alternate Valuation Date Election

The default rule is that property is valued for step-up purposes on the decedent's exact date of death. But the executor of an estate may elect to use an alternate valuation date six months after the date of death, as authorized by Section 2032 of the Internal Revenue Code. The election applies to all assets in the estate, not asset by asset.

This election is more nuanced than it appears. The executor can choose the alternate date only if it lowers both the value of the gross estate and the total federal estate tax owed. For estates below the $15 million exemption, no estate tax is owed on either date, so the election is unavailable — even if values dropped sharply in the six months following death.

When the election is available, executors must weigh the trade-off carefully. A lower estate value means lower estate tax, but it also means a lower stepped-up basis for heirs. Heirs who plan to sell soon will face larger capital gains in the future. The election can save estate tax in the short term and cost income tax in the long term.

Common Mistakes That Erase the Benefit

The step-up rule is automatic, but realizing its full value requires good documentation and good decisions. Here are the most common ways families lose money they were entitled to:

Failing to document fair market value at death. The IRS does not assume a value — your heirs do. For real estate, this means commissioning a date-of-death appraisal from a certified appraiser. For closely held businesses, it means a formal business valuation. For publicly traded securities, it means recording the average of the high and low trading price on the date of death (or the prior trading day if death occurred on a weekend or holiday). Without contemporaneous documentation, the IRS may challenge the basis years later when the heir sells, and reconstructing values after the fact is painful and expensive.

Gifting appreciated assets during life instead of bequeathing them at death. A lifetime gift carries the donor's original basis (called "carryover basis"). Parents who gift the appreciated beach cottage to their children during their lifetime hand them a $90,000 basis instead of a $1.2 million stepped-up basis. Unless there is a compelling reason to remove the asset from the estate, holding appreciated assets until death is almost always the better tax outcome.

Putting children on the deed to a family home. This well-meaning move to "avoid probate" is a partial gift during the parent's lifetime. The child's portion of the home does not get a step-up at the parent's death — it carries the parent's original basis. A revocable living trust or a transfer-on-death deed achieves the probate-avoidance goal without sacrificing the step-up.

Co-mingling community and separate property. Couples in community property states sometimes lose the double step-up on assets that originally belonged to one spouse but were treated as joint property over the years. Maintaining clear records of community property status is critical. A community property agreement can formalize the treatment in writing.

Forgetting state-level differences. Twelve states and the District of Columbia impose their own estate or inheritance taxes, often with much lower exemptions than the federal $15 million. State rules around alternate valuation, basis adjustments, and reporting can differ from federal rules.

Why Bookkeeping Matters Here

The step-up in basis rule requires the heir to know two numbers at every future sale: the date-of-death fair market value and any post-death adjustments (improvements, depreciation taken on rental property, additional purchases, partial sales). Lose track of those numbers, and the heir is at the mercy of whatever records the brokerage, recorder of deeds, or appraiser happens to retain.

Heirs who inherit complex portfolios — brokerage accounts with hundreds of lots, real estate holdings, family business interests — should set up a clean record-keeping system on day one. Track the stepped-up basis for each asset, the date and source of the valuation, and any subsequent adjustments. Years from now, when the heir sells and the IRS asks for substantiation, that documentation is the difference between a smooth filing and a costly audit.

For multi-asset estates, plain-text accounting tools shine. They let you record basis adjustments with clear narration ("step-up to FMV at death of [decedent], appraisal dated [date]"), version-control the file alongside the supporting documents, and audit every change. There is no proprietary database to lose access to and no vendor to depend on years from now when the heir finally sells.

Looking Ahead: Will the Step-Up Survive?

The step-up in basis has been a frequent target of tax reform proposals from both political parties. Critics argue it primarily benefits wealthy families and creates a "lock-in effect" that discourages older Americans from selling assets that would otherwise be put to more productive use. Defenders argue that eliminating it would impose double taxation on assets already subject to estate tax and would create administrative chaos around tracking basis across generations.

For now, the rule is intact and was explicitly preserved by the 2025 legislation that reshaped much of the rest of the federal tax landscape. But planning around the step-up should be flexible enough to adapt if the rule is curtailed in the future. Building in optionality — through revocable trust structures, regular basis tracking, and careful gifting decisions — keeps your options open.

Keep Your Financial Records Clear from Day One

Whether you are planning your own estate or stepping into the role of executor for a parent or relative, accurate basis records are the foundation of every step-up calculation. The savings are too large — and the audit risk too real — to leave to memory or scattered paperwork. Beancount.io provides plain-text accounting that gives you complete transparency and version control over basis records, valuation dates, and supporting documentation. Get started for free and see why developers, finance professionals, and families managing complex estates are switching to plain-text accounting.