Doctors: Your CPA Isn’t Dodging You—You’re Asking the Wrong Question
Why “Can I write off my Ferrari?” turns into a 10-step tax analysis
You’re an ER doc.
A patient comes in with shortness of breath.
CT scan confirms a pulmonary embolism (a blood clot in the lung).
You quickly think about bleeding risk, kidney function, contraindications.
But at a high level, the logic is simple:
There’s a clot → you thin the blood.
Treatment?
Blood thinner.
Done. Easy Peasy.
Even a medical assistant can follow that reasoning.
So Why Doesn’t Tax Work Like This?
As both a physician and a tax professional, I’ve realized something:
In tax…
We generally can’t just say:
“I bought something useful → therefore I can write it off.”
Meet Dr. Nip Tuck
Dr. Nip Tuck is a successful Beverly Hills plastic surgeon.
Celebrity clientele
Luxury lifestyle.
Brand-conscious.
One day, he walks into his tax advisor’s office and says:
“Hey… I just bought a Ferrari.
Can I write it off?”
This is where things get complicated.
Because in tax…
There is rarely an answer as simple as the “blood thinner” answer.
Step One: What World Is Dr. Nip Tuck In?
Before deductions even come into play, you have to classify the activity he is engaged in as a plastic surgeon.
There are four basic “worlds” of activity in the tax code:
Trade or business activity (IRC §162).
Investment/income‑production activity (IRC §212)
Hobby/not‑for‑profit activity (IRC §183)
Personal activity (IRC §262)
So the real question is not:
“Is the Ferrari deductible?”
It’s:
“What activity world is Dr. Nip Tuck operating in?”
Step Two: Is This Actually a Business?
Dr. Nip Tuck needs to be in the §162 “trade or business” world to even argue for a Ferrari write‑off.
So how do we determine that?
We apply the Supreme Court’s standard from Commissioner v. Groetzinger:
Is he operating with continuity and regularity?
Is his primary purpose income or profit?
If not → no §162 trade or business.
Game over.
No business deduction.
Step Three: Is It Ordinary and Necessary?
Let’s say Dr. Nip Tuck clearly passes the trade‑or‑business test.
To deduct a business expense, §162 says the expense must be “ordinary and necessary.”
What does that mean in plain English?
From Welch v. Helvering and later cases:
Ordinary = common or usual in that line of work
Necessary = appropriate and helpful (not necessarily essential)
Now the real question becomes:
“Is owning a Ferrari common and appropriate for how Dr. Nip Tuck runs his practice?
For most doctors… no.
But for a Beverly Hills plastic surgeon whose whole brand is ultra‑luxury, VIP service, and high‑end image?
Now you at least have an argument that it supports the business brand.
Still not a guarantee.
The IRS (or a court) can still say:
“This looks “too personal” or “not reasonable for this business.”
Step Four: The Tax Code That Can Botch Dr. Nip Tuck’s Write‑Off Plan
Let’s say Dr. Nip Tuck clears all of that.
He has a real business.
The Ferrari genuinely supports his brand.
It’s arguably ordinary and necessary in his specific niche.
He’s ready to write it off using bonus depreciation under §168(k).
Right?
Not so fast.
Enter §280F - the infamous “luxury auto” limitation rules.
Even if everything else works, §280F puts hard dollar caps on how much depreciation (including bonus) he can claim on a passenger car like a Ferrari.
Think roughly $60k-$70K total over several years.
Not even close to a full write-off on a $700K supercar.
Change One Fact, Change the Outcome
Now Dr. Nip Tuck makes a different move.
Instead of a Ferrari…
He buys a Bentley Bentayga with a gross vehicle weight rating (GVWR) over 6,000 pounds.
Now the rules shift:
Vehicles over 6,000lb are generally not treated as “passenger automobiles” under §280F, so the luxury auto caps may not apply.
The Bentayga may now qualify for 100% bonus depreciation under §168(k) (federally).
But then…
California steps in.
California does not conform to federal bonus depreciation under §168(k).
So:
Federal return → potentially 100% deduction in Year 1
California return → deduction spread over multiple years (no bonus allowed).
Same car.
Same purpose.
Same business.
Completely different outcome - just because of federal vs. state rules.
And Dr. Nip Tuck Is Still Not Done
Even if everything above checks out…
There are still more limitations:
§469 Passive activity rules
§465 At‑risk rules
Let’s say Dr. Nip Tuck takes a long sabbatical and stops materially participating in his plastic surgery practice.
Now, his activity may be considered passive.
Result?
The losses from that Bentayga become passive losses—
only usable against passive income, not his active surgical income.
But we’re still not done.
Enter §465.
Now the question becomes:
How much money is he actually at risk of losing?
If his loss exceeds his at-risk amount, the excess is suspended until:
He puts more money at risk, or
He sells/disposes of the activity
At this point, Dr. Nip Tuck is thinking:
“This is way more complicated than I expected.”
Exactly.
Why Tax Feels So Frustrating
In medicine:
A high‑level answer is often good enough.
In tax:
A high‑level answer is often wrong.
Because tax is not a one‑step system.
It’s a sequence that must be followed precisely:
Classify the activity (business, investment, hobby, personal)
Determine whether the expense is ordinary and necessary.
Apply the relevant Code sections (autos, bonus depreciation, etc)
Apply limitations (basis, at‑risk, passive activity, state differences)
Look for exceptions and special rules
Only then do you get your answer.
Why Your Tax Advisor Says “It Depends”
So when Dr. Nip Tuck asks:
“Can I write off my Ferrari?”
And his tax advisor says:
“It depends…”
They’re not being difficult.
They’re being prudent.
Because in tax…
Skipping the sequence doesn’t give you a faster answer—
it gives you the wrong one.
And in tax, the wrong answer is the most expensive one.
Final Thought
Tax is not like medicine.
A simple question often requires layered analysis.
Miss one layer…
And the entire conclusion can fall apart.
That’s how expensive tax mistakes happen.
If you want to stop asking “Can I write this off?”
and actually understand how the tax code works—
Follow me.
I’ll walk you through it the way it actually works in real life.