Qualified Improvement Property: The Most Valuable Bucket in a Commercial Building

A drafting error in the 2017 tax law trapped billions of dollars of renovation deductions at 39 years instead of 15 (for two full years) before Congress went back and fixed it retroactively.

If you renovated a commercial building between 2018 and 2020 and nobody caught it, that deduction might still be sitting on your return, waiting to be claimed.

And, you can still use it TODAY on new property.

That’s the short version of why qualified improvement property is worth understanding.

QIP is a high-leverage depreciation bucket in a commercial building (15-year life, fully bonus-eligible),  but only if you know what actually counts, that it’s commercial-only, and who’s allowed to claim it.

Get those three things right, and you pull a renovation’s worth of deductions into year one. Get them wrong, and you depreciate the same dollars over four decades.

What Is QIP?

Start with the definition, because almost every mistake here is a definition mistake.

Under §168(e)(6), qualified improvement property is an improvement made by the taxpayer to the interior portion of a nonresidential building, placed in service after the building was first placed in service.

And the statute carves out three things that look like improvements but are specifically not QIP:

• Any enlargement of the building (added square footage, additions)
• Elevators and escalators
• The internal structural framework

So a tenant build-out, new interior walls, lighting, flooring, ceilings, interior finishes — that’s the QIP zone.

Knocking out a wall to expand the footprint, the elevator you installed, the load-bearing bones of the building — not QIP.

The Mistake that Costs Investors the Most

The mistake is assuming residential property qualifies. It doesn’t. QIP is nonresidential only.

The interior renovation on your apartment building or your single-family rental is not QIP, no matter how nice it looks.

This is the number-one error I see real estate investors make, because they hear “15-year bonus-eligible improvements” and assume it applies to everything they own. It applies to your commercial assets.

However, this means STRs CAN apply… if the property is already being used in a non-residential capacity. Think, previously used STR purchased.

The second mistake is reaching for exterior, roof, or structural work. Interior only. If it’s holding the building up or sitting on the outside of it, it’s not in the bucket.

The “Retail Glitch” and the CARES Act Fix

Here’s the history, because it’s still putting money back on people’s returns.

When the TCJA passed in 2017, the intent was clear: QIP would be 15-year property, eligible for 100% bonus depreciation. But the statute that came out the other end didn’t say that. Through a drafting error (the famous “retail glitch”), QIP was left without a 15-year class life, which defaulted it to 39-year property and made it ineligible for bonus.

So for 2018 and 2019, businesses that renovated commercial space were stuck depreciating it over 39 years, straight-line, when everyone knew Congress had meant to let them write it off immediately.

The CARES Act fixed it in 2020. Section 2307 retroactively amended §168(e)(3)(E) to give QIP its 15-year class life, amended §168(e)(6) to add the “made by the taxpayer” language, and set the ADS recovery period at 20 years under §168(g)(3)(B).

Critically, the fix was effective as if it had been included in the TCJA, meaning it reached all the way back to property placed in service on or after January 1, 2018.

At the time, Rev. Proc. 2020-25 gave taxpayers a clean path to go back and grab the depreciation they’d missed on 2018–2020 QIP.

Where the Money Still Hides

That formal Rev. Proc. window has since closed, but the deduction didn’t evaporate.

If you depreciated QIP from 2018 onward over 39 years — an impermissible method, now that the law says 15 — the fix today is a Form 3115, a change in accounting method.

It carries a §481(a) adjustment that sweeps the entire missed deduction into the current year in one shot. No stack of amended returns. If you did a commercial build-out in the last several years and it’s been crawling along at 39 years, this is a real, recoverable number.

Bonus, §179, and the OBBBA Reset

Why does the 15-year life matter so much? Because bonus depreciation under §168(k) is only available for property with a recovery period of 20 years or less. QIP’s 15-year life slides in under that ceiling.

The 39-year version didn’t, which is the whole reason the glitch hurt.

Now the rate, and here’s where you have to watch the calendar:

Under the old TCJA phase-down, bonus was stepping down — 80% in 2023, 60% in 2024, and 40% in early 2025. The OBBBA stopped that and restored 100% bonus depreciation, permanently, for property acquired and placed in service after January 19, 2025.

One catch worth flagging: property placed in service in that sliver between January 1 and January 19, 2025, still falls under the old 40% rate. After the 19th, you’re back to writing off the whole thing.

There’s also a fork worth understanding: QIP is eligible for both bonus and §179 expensing. They’re not the same tool. §179 — which the OBBBA expanded — lets you pick specific assets and reaches some real-property categories that bonus can’t, but it’s capped and limited by your taxable income, so it can’t create a loss.

Bonus is automatic, unlimited, and now permanent. For most investors with a real renovation, bonus is the workhorse, and §179 is the scalpel for specific situations. Which one wins depends on your income picture and what else you’re expensing that year.

The mistake here is passive: letting the software default a commercial build-out to 39-year straight-line because nobody told it otherwise.

The QIP treatment isn’t automatic in the sense that someone has to actually identify it. If no one’s looking, you’ll quietly depreciate over 39 years, a cost you could have written off this year.

Who Can Claim it and the §163(j) Trap

Two words in the definition decide who gets QIP at all: “made by the taxpayer.”

That means you have to have made the improvement.

You can’t buy a building, point at the renovations the prior owner did, and reclassify them as your QIP. The improvement has to be yours. (This is also why a cost segregation study is the practical tool here — it’s how you identify and carve out the QIP alongside the 5-, 7-, and 15-year §1245 components in your study.)

And here’s the trap that ties this blog to the §163(j) piece. If you made the §163(j)(7)(B) real property trade or business election — the one that lets you escape the business interest limitation — then §168(g)(1)(F) drags your QIP onto the 20-year Alternative Depreciation System.

And property required to use ADS is excluded from bonus by §168(k)(2)(D).

So the election that frees up your interest deduction simultaneously kills bonus on your QIP. Those two benefits are in direct tension. You don’t get to make the RPTOB election in a vacuum and assume your QIP bonus survives — it doesn’t. Model them together.

What This Costs You Later

QIP bonus is fast depreciation, and fast depreciation comes home at sale.

The QIP you wrote off is §1245-flavored, which means the deduction comes back as ordinary recapture — up to 37% — when you sell. Same story as the rest of your cost seg components, and the reason the sale allocation between buckets matters so much.

The front-loaded deduction isn’t free money; you’re trading a deduction at ordinary rates now against recapture at ordinary rates later, and the time value of money is what makes it worth doing.

Just don’t be surprised at the closing table.

And if you elected RPTOB, the counterpoint is the opposite problem: your QIP is on a 20-year straight-line crawl with no bonus at all, which defeats the entire purpose of identifying it. Know which lane you’re in before you renovate.

What To Do With This

• If you own commercial property and have renovated interiors any time since 2018, ask whether QIP was actually identified — and whether a Form 3115 can recover bonus you missed. This is the most common place I find real money.
• On any new commercial build-out or tenant improvement, run a cost seg to separate the QIP and the §1245 components before you file, not after.
• Confirm the asset is nonresidential. Residential interior work is not QIP — full stop.
• Coordinate with your §163(j) position. If you’ve made, or are considering, the real property trade or business election, your QIP loses bonus. Decide which deduction is worth more before you elect.
• Model it, don’t assume it. A five-minute classification review on a recent renovation can surface a catch-up deduction you’ve been leaving on the table for years.

Whether you’re planning a renovation, completing a cost segregation study, or reviewing prior-year returns for missed opportunities, proactive tax planning can help you accelerate deductions and avoid costly mistakes.

Schedule a consultation today.