If you’ve inherited assets, how step up basis works comes down to one mechanic: the tax code resets your cost basis to the asset’s fair market value on the date of the original owner’s death. That means when you sell, you only owe capital gains on appreciation that occurred after you inherited—not on the decades of growth your parent or spouse enjoyed. For a $300,000 brokerage account that was originally purchased for $40,000, your new basis is $300,000; sell the next day and you owe $0 in federal capital gains. This reset is why inherited property is such a powerful wealth-transfer tool, but the rules are far from automatic, and as a practitioner who has closed several estates, I can tell you the paperwork decides whether you keep the benefit.
How Step Up Basis Works in Plain Terms (And the Hidden Step-Down)
The legal term is stepped-up basis, but practitioners often call it a “basis reset.” Under Internal Revenue Code § 1014, the heir’s basis in inherited property equals the asset’s fair market value (FMV) at the decedent’s death. If the estate executor elects the alternate valuation date, the basis uses the value six months after death.
Why Basis Reset Beats Carrying Over Cost
Without the step-up, heirs would inherit the decedent’s original cost. On a stock bought for $10,000 that grew to $500,000, a carryover basis would trigger tax on $490,000 when sold. The reset eliminates that historical gain for federal capital gains purposes. It is not an exemption from tax; it is a re-marking to market at a specific moment.
The reset also starts a fresh holding period. The IRS treats inherited assets as long-term regardless of how long the decedent held them. That means any sale after inheritance qualifies for the lower long-term capital gains rates, even if you sell the next day.
The Step-Down Nobody Warns About
Most people don’t realize the rule cuts both ways. If the asset had fallen below the decedent’s original purchase price, you receive a stepped-down basis. I once advised a family who inherited a vacation condo that the grandfather bought for $250,000 in 2007; by his passing in 2022 it was worth $180,000. Their basis was $180,000, not $250,000, which meant a later sale at $210,000 produced a $30,000 taxable gain they didn’t expect.
The thing nobody tells you about step-up is that it only applies to assets included in the decedent’s taxable estate. Property transferred via a completed gift during life, or held in certain irrevocable trusts, may bypass the rule entirely. That distinction is where many heirs trip up.
For a quick orientation, the core formula is: Taxable gain = Sale price − Inherited basis (FMV at death). The clock for long-term vs short-term capital gains treatment starts fresh on the inheritance date, so any sale after one year qualifies for lower long-term rates.
A $300,000 Inheritance Scenario: Walking Through the Math
Let’s answer the question I hear constantly: “Do I have to pay capital gains if I inherit $300,000?” The receipt of the inheritance is not a taxable event. You only face capital gains when you dispose of the asset. To see this, imagine you inherit a portfolio of dividend stocks worth exactly $300,000 on the date of death. The decedent had paid $75,000 decades earlier.
Cash vs Securities vs Real Estate
If the $300,000 is cash in a bank account, there is no capital gain—cash is cash. If it is marketable securities, your basis becomes $300,000. If it is a single-family rental worth $300,000 (with an old basis of $100,000), the same reset applies, but you must also allocate improvements and depreciation recapture differently post-inheritance.
In the securities example, your new basis is $300,000. If you sell the entire stake the following week for $302,000, your taxable gain is $2,000. If instead you hold for three years and sell at $400,000, you owe tax on $100,000 of appreciation. The original $225,000 gain inside the decedent’s lifetime vanishes for federal purposes.
Holding Period and Long-Term Rates
Because inherited property is automatically long-term, the $100,000 gain in the previous example faces 15% or 20% federal rates depending on your income, not the higher short-term ordinary rates. For a deeper dive on how that gain interacts with your overall liability, see our guide to calculating tax brackets by hand.
To model your own numbers, use our Step-Up Basis Calculator before you list anything for sale. The calculator lets you toggle the alternate valuation date and state rates.
Tax rate context matters. For 2024, single filers with total taxable income up to $47,025 enjoy a 0% long-term capital gains rate. If the inherited $300,000 is your only asset and you have low other income, even a post-inheritance gain could be tax-free at federal level. State rates vary from 0% to over 13% in California, so location remains key.
What If You Inherit $300k in a House?
Suppose the $300,000 is a home that was the decedent’s primary residence. You still get the step-up, but if you later sell it as an heir who does not live there, you won’t qualify for the $250,000/$500,000 primary residence exclusion. Your taxable gain is sale price minus $300,000. If you move in and use it as your residence for two of the next five years, you may combine the step-up with the exclusion—an advanced maneuver worth planning.
One edge case: what if the asset is worth $300,000 at death but you don’t get appraised until nine months later when it’s worth $330,000? Your basis remains the date-of-death value ($300,000), not the later higher number. The appraisal date does not shift the basis unless the executor formally elects the alternate date and the asset is still held then.
The 6-Month Alternate Valuation Rule Most Heirs Ignore
What is the 6 month rule for stepped-up basis? It refers to the alternate valuation date permitted under 26 U.S. Code § 2032. The executor of the estate may choose to value all estate assets as of six months after the decedent’s death, rather than at death.
Eligibility Criteria for the Election
The election is available only if it either decreases the gross estate value or increases the estate’s liquidity for tax payment. It is all-or-nothing: you cannot pick the higher date for one asset and lower for another. The executor must file IRS Form 706 and check the box; silence defaults to date-of-death valuation.
This election is not automatic and it’s all-or-nothing for the entire estate. It only makes sense if the total estate value drops during those six months, reducing estate tax or providing a lower basis that matches a subsequent sale price. I’ve seen executors use it after a market crash in early 2020: assets fell 15% by September, so the alternate date cut both the estate tax bill and the heirs’ later capital gains when they sold at the lower level.
Real Number Example of the 6-Month Election
Imagine an estate with $12 million in stocks at death in January, and the federal exemption is $13.61 million. By July, stocks fall to $10 million. Electing alternate valuation drops estate value below exemption, saving roughly 40% estate tax on the difference. Heirs later sell at $10.5 million; their basis is the July value ($10 million), producing only $500k gain. Without election, basis would be $12 million and sale would yield a loss—but estate tax would have applied. The trade-off is real.
The trade-off is documentation. The executor must file IRS Form 706 and explicitly elect the alternate date. If the estate is below the federal exemption ($13.61 million per person in 2024, indexed later), most families skip the election because there’s no estate tax to save. But skipping it can be a mistake if the assets later rebound and you sell soon after—your basis stays at the higher death-date value, which is good for gain but bad if you wanted a lower estate valuation.
Critically, the alternate valuation date only applies if the asset is still owned by the estate at that six-month mark. If the executor liquidates the brokerage account at month two, that specific asset’s basis is the death-date value, not the alternate date. This nuance trips up DIY estates constantly.
What Assets Do Not Qualify for a Step-Up in Basis
Not every transferred asset gets the reset. The following checklist covers the common non-qualifying categories I review with clients:
- Retirement accounts: Traditional IRAs, 401(k)s, 403(b)s, and similar qualified plans. Heirs pay ordinary income tax on distributions; there is no capital gain basis adjustment.
- Roth IRAs: Distributions may be tax-free, but the account itself does not receive a stepped-up basis because there was no pre-tax gain to begin with.
- Assets gifted during the decedent’s life: If mom gave you the stock in 2015, your basis is her original basis (carryover). The step-up only applies to assets owned at death.
- Certain irrevocable trusts: Property in a completed irrevocable trust that is not included in the estate typically bypasses § 1014.
- Annuities and life insurance proceeds: Generally income-tax-free to beneficiaries and have no capital basis concept.
- Assets with a contractual pass-through: Some partnership interests may have varying basis treatment; consult the partnership agreement.
Joint Ownership and Tenancy Nuances
Property held as joint tenants with rights of survivorship (JTWROS) between non-spouses gets a step-up only on the decedent’s fractional share. If two siblings owned a $400,000 lake house 50/50 and one dies, the survivor’s basis is $200,000 (half of date-of-death value) plus their own original $200,000, totaling $300,000. That partial step-up is often missed.
In community property states, the surviving spouse often gets a full step-up on both halves at the first death—a major exception to the fractional rule. We’ll detail that later.
Trust Types Compared
A revocable living trust is ignored for basis purposes because the assets are in the grantor’s estate. An irrevocable grantor trust may still be included if the grantor retained certain powers. A truly independent irrevocable trust (e.g., a dynasty trust) usually escapes both estate tax and step-up, meaning heirs take carryover basis. The most frequent miss is assuming an inherited house inside a revocable living trust gets no step-up. In reality, because the trust is grantor and included in the estate, the home absolutely receives the reset.
For a quick verification, ask: “Was the asset includable in the decedent’s gross estate for federal estate tax purposes?” If yes, step-up likely applies. If it was given away or parked in a non-grantor trust, it probably does not.
Common Mistakes With Stepped-Up Basis (Including My Own)
What are common mistakes with stepped-up basis? The first is failing to establish the date-of-death fair market value. When I first helped settle my uncle’s estate, I lazily used his 2009 purchase confirmation for a rental property. The IRS later questioned the sale, and we had to pay a penalty because we couldn’t prove the stepped-down value after a market dip.
My Costly Appraisal Miss
The property was a small office building. I assumed the county tax assessment was close enough. It wasn’t. The IRS audited the heir’s return three years later, proposed a basis of the original 1998 cost, and the extra gain plus accuracy-related penalty cost the family about $38,000. That experience is why I now insist on a licensed appraisal for any real estate over $50,000.
Other Frequent Errors
- Assuming cash and retirement funds get the same treatment as brokerage stocks.
- Selling an asset before the estate closes and guessing the basis, then amending later.
- Ignoring state estate or inheritance taxes that may have different basis rules.
- Missing the executor’s deadline to elect alternate valuation.
- Combining inherited property with jointly owned marital property, muddying the basis split.
- Believing the step-up applies to assets the decedent gifted to a trust years before death.
A further error is misunderstanding the audit window. The IRS generally has three years to challenge a return, but six years if you omit more than 25% of income. A botched basis that underreports gain can trigger the longer window, extending your exposure well beyond the usual period.
Another subtle trap: heirs sometimes hold the asset and pass it to their own children, assuming the basis steps up again. It does—but only at the heir’s death, and only to the then-current FMV. The interim appreciation during your lifetime is taxable when you sell.
The thing nobody tells you about mistakes is that the burden of proof sits with the heir. The IRS does not send a “your basis is X” letter. If you can’t produce a qualified appraisal or brokerage statement dated at death, you may default to the decedent’s original cost, which maximizes your gain.
The Heir’s Step-Up Documentation Playbook
After handling a dozen estates, I built a simple framework—the Heir’s Step-Up Checklist—to lock in the correct basis before any sale:
- Secure date-of-death valuations: For publicly traded stocks, pull the closing price on the death date from a reliable source. For real estate, hire a licensed appraiser.
- Identify non-qualifying assets early: Separate IRAs and gifted property from the estate pool using the checklist above.
- Coordinate with the executor: Ask whether Form 706 will elect the 6-month alternate date. Get it in writing.
- Open a separate brokerage sub-account: Track inherited lots separately from your own to avoid commingling.
- Run the numbers with the calculator: Use our Step-Up Basis Calculator to project tax under hold vs sell scenarios.
- Retain records for seven years: Keep appraisals, estate tax returns, and brokerage statements with the heir’s file.
- Reconcile K-1s from estates: If the estate distributes assets in kind, the K-1 should report the basis; match it to your evidence.
Loss Harvesting Insight
Most people don’t realize that a step-up basis can also create a capital loss opportunity. If you inherit at $100k and sell at $90k, you realize a $10k long-term capital loss because your basis was $100k. That loss can offset other gains—something few heirs think to harvest. In a declining market, this can turn a grim inheritance into a small tax silver lining.
This playbook turns a vague entitlement into defensible tax positioning. The limitation is that it requires executor cooperation; if the estate is contested, valuations may be delayed and you’ll need to file for an extension on any related sale reporting.
If the estate is complex, engage a fiduciary CPA or enrolled agent; the fee is trivial compared to a 20% accuracy penalty plus interest. I have yet to see a do-it-yourself estate with more than three assets that didn’t miss at least one valuation detail.
State Tax Nuances and Community Property Twists
Federal rules are only half the story. Nine states (including California, Texas, Arizona, New Mexico, Nevada, Louisiana, Wisconsin, Idaho, and Washington) follow community property laws that can grant a double step-up on jointly held spousal assets: both halves of the property get reset to FMV at the first spouse’s death, not just the decedent’s half. This is a massive benefit unavailable in common-law states.
State Estate Tax Thresholds
Some states impose their own estate or inheritance taxes with exemption thresholds far lower than federal levels (e.g., Oregon and Massachusetts at $1 million, Maryland at $5 million). In those states, the alternate valuation election may matter even for middle-class estates. Additionally, a handful of states (like Pennsylvania) tax inherited retirement accounts differently, so the non-qualifying asset list must be reviewed locally.
Practitioner insight: always check the decedent’s state of domicile at death, not just where the property sits. I’ve seen a Florida resident owning New York real estate avoid NY estate tax due to domicile rules, but the basis step-up still applied under federal § 1014 regardless.
Community Property States List
If you are in a community property state and the asset was acquired during marriage, the survivor’s basis after first death is 100% stepped up. For example, a $600,000 home with original joint cost $200,000 becomes basis $600,000 for the survivor. In a common-law state, only $300,000 (the decedent’s half) steps up, leaving $100,000 carryover on the survivor’s half.
States like New Jersey impose an inheritance tax on siblings or nieces but not on spouses or children, yet the federal step-up still applies regardless of state death tax. The interplay means you might owe state inheritance tax on the receipt but face no capital gains until sale—a double-layer timing mismatch heirs should map early.
When to Sell, Hold, or Elect Alternate Valuation: A Decision Matrix
To make the abstract concrete, here is a decision matrix I use with clients:
| Scenario | Recommended Action | Reason |
|---|---|---|
| Asset qualifies, need cash | Sell soon after death | Reset basis minimizes gain; long-term rates apply |
| Asset qualifies, volatile market | Hold | New basis shields past gain; future gain taxable |
| Estate over state threshold, values dropped | Executor elects 6-month date | Lowers estate tax and aligns basis |
| IRA or gifted asset | Plan distributions in low-income years | No step-up; ordinary income tax applies |
| Asset stepped-down below original | Consider selling to harvest loss | Inherited basis may exceed sale price |
Scenario: Rising Market vs Falling Market
In a rising market after death, the date-of-death valuation locks in a lower basis, which is great when you sell later at higher prices. In a falling market, the alternate valuation election can lower basis further, but only if the estate benefits overall. I advise clients to model both with the calculator before the executor’s decision deadline (the filing of Form 706, generally nine months after death, with extension).
How step up basis works is ultimately a timing and documentation game. The law gives you a reset, but only if you prove the value and respect the boundaries of what’s included in the estate. Use the checklist, run the calculator, and coordinate with the executor before any sale hits the market.
The honest limitation: Congress has proposed eliminating or capping step-up repeatedly. As of this writing the rule stands, but practitioners should revisit basis strategy every year because legislative risk is real. Plan for the law you have, but document as if you’ll need to defend it a decade from now.