A client recently came to us in a panic. Her elderly mother was about to sell a collectible car for $100,000, and she'd been told she'd owe capital gains tax on $95,000 of it. The right step-up-basis analysis dropped that gain to ~$12,000 and saved her family roughly $20,000-$30,000 in tax. Most CPAs never asked the question that made it possible.
What "step-up basis" actually means
When you inherit an asset, the IRS resets its tax basis to fair-market value as of the date of death. Not the price the original owner paid for it. The price it was worth when the previous owner died. That reset is called a "step-up" because it usually steps the basis UP (assets tend to appreciate), which means when the inheritor eventually sells it, the taxable gain is calculated from the much higher inherited basis — not the original purchase price.
This applies to nearly any appreciating asset: real estate, stocks, collectibles, business interests, classic cars, art, jewelry. It's one of the most generous provisions in the tax code, and it's wildly under-utilized because people don't know to look for it.
The case in detail (anonymized)
The client
Doctor in New Jersey. His mother (NJ, widowed) was planning to sell a 1970 Chevrolet collectible car she'd kept since her husband passed in 2005.
The number she was told
Original basis: $5,000 (what husband paid back in the day). Sale price now: $100,000. Reported gain: $95,000. At long-term capital gains rates (her bracket: ~20% federal + ~9% NJ) that's roughly $27,000 in tax.
What we asked
"When did your husband pass? Was the car appraised at the time?" The car was valued at $150,000 in 2005 for estate purposes. NJ is a non-community-property state, so the half her husband owned stepped up to fair-market value on his death — $75,000 became her basis on that half.
The recalculation
Her real basis was now: $2,500 (her original half) + $75,000 (stepped-up half) = $77,500. Sale at $100,000. Real gain: $22,500 long-term — but only $12,000 of it taxable after applying her capital loss carryforward from another investment.
The save
Tax dropped from ~$27,000 to roughly ~$3,500. Net family savings: ~$23,500. Time invested: one phone call + one follow-up.
Why most CPAs miss it
Three reasons:
- They never ask. A typical CPA looks at the sale, computes the gain off the cost basis on the client's statement, and moves on. They don't ask "when did you acquire this?" because they assume the cost basis is correct.
- The original spouse died years ago. If the death was 10+ years back, the client may not even mention it. The stepped-up basis lives in the estate file from a decade ago.
- It requires documentation work. You need the date-of-death appraisal (or a reasonable post-hoc valuation). That's effort, and many preparers won't do that effort during tax season.
Where else this applies
🏠 Inherited home
Bought for $50K in 1980, worth $600K at parent's death, sold for $650K today. Gain is $50K, not $600K.
📈 Inherited stock
Apple stock bought in 1995 for $1K, worth $400K at death. Sold today for $420K. Gain is $20K, not $419K.
🏢 Inherited business interest
Parent's S-corp shares stepped up to FMV at death. Hugely beneficial if you sell the business after the transfer.
💍 Inherited collectibles
Jewelry, art, watches, classic cars — every category we've ever helped a client unwind has had step-up opportunities.
What to do if this applies to you
Before selling anything you inherited, talk to a tax advisor who actually asks questions. Bring:
- • Approximate date of the previous owner's death
- • Any appraisals, real-estate tax assessments, or financial-statement values from around that time
- • Estate documents if you have them (the executor's records often have the date-of-death valuations)
Even an estimated value can work — the IRS accepts reasonable post-hoc appraisals as long as the methodology is sound. We've helped clients reconstruct valuations 15+ years after the fact.
Got an inherited asset you're thinking about selling?
This is exactly the kind of question we ask in every onboarding call. One conversation could save you tens of thousands.
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