What cost segregation studies cost, and when the tax benefits are worth it

A cost segregation company prices the engineering work, then holds the fee fixed. A percentage of projected tax savings is a warning sign, because it pays the provider to be aggressive with your allocation.

What you are buying is a defensible reclassification. Residential rental property depreciates over 27.5 years and commercial property over 39 years, and cost segregation studies move whatever is not really the building structure onto a shorter tax life.

Ask for the fee in writing, ask whether a site visit is included, and ask whether audit support is included or billed separately. The last one is where quotes that look similar stop being similar.

You do not need a rule of thumb. You need four numbers, and you already have three of them.

• Depreciable basis. Purchase price less the land allocation. Land is never depreciable, so a high land value market changes this more than people expect.
• Reclassified share. The portion the study is expected to move to 5, 7 and 15-year lives. A furnished short-term rental normally carries a higher share than a bare long-term rental.
• Your tax rate. Your federal tax bracket plus New Jersey, though the New Jersey part behaves differently. See the last section.
• Whether the loss is usable. This is the one people skip, and it decides everything.

Multiply basis by the share the study can reclassify, apply 100 percent bonus depreciation, then multiply by your tax rate. That is the first-year tax savings, and the cash flow it frees up is the real benefit of cost segregation. Compare it to the cost of the study. A study that returns a small multiple of its own cost in year one is usually worth doing. One that barely clears the fee is not.

The fourth point overrides the other three. If your rental loss is passive and stays suspended, the study converts a small suspended loss into a large suspended loss and changes your tax bill by nothing. Confirm usability first, using the short-term rental rules or real estate professional status.

The cheap options are not selling you a different price for the same thing. They are selling you a different thing.

The IRS sets out what it expects to see in Publication 5653, its Cost Segregation Audit Techniques Guide, which examiners use when they review a study. It favours approaches built on actual construction costs and engineering analysis of components over allocations based on rules of thumb or on residual estimates.

A software-generated estimate can be a reasonable way to decide whether to commission real work. It is a weaker foundation for a large deduction on a return that gets examined, and the cost of defending a weak allocation can exceed the fee you saved.

That is the practice's position on this generally. A deduction you cannot document is not a saving yet.

Most of the delay is document gathering, not engineering. Have these ready and the timeline shortens considerably.

• The closing statement and purchase price allocation
• The appraisal, which usually carries the land value
• Construction, renovation or improvement invoices if you have built anything
• Blueprints or floor plans where they exist
• A site visit, or a thorough set of photographs of every room and the exterior
• Your depreciation schedule from the prior return

Plan in weeks rather than days once the engineer has the file, and start well before a filing deadline rather than during one.

Missing the study in the year you bought does not close the door.

A look-back study lets you claim the depreciation you could have taken. It is handled as a change in accounting method on Form 3115, with a section 481(a) adjustment that brings the catch-up into the current year. You do not amend the earlier returns.

The fee is usually a little higher for a look-back because of the extra computation, and the depreciation deductions land in a single tax year, which makes the tax planning question sharper rather than softer. A taxpayer with a low-income year ahead may do better waiting.

Every national provider quoting you a benefit is quoting the federal one. New Jersey gives you a fraction of it.

New Jersey decoupled from federal bonus depreciation for gross income tax purposes in 2004 and caps Section 179 at $25,000, so the accelerated portion largely does not exist on the NJ-1040. The difference is tracked on Form GIT-DEP, and your New Jersey basis in the property diverges from your federal basis from that point on.

There is a second limit on top. A New Jersey rental loss sits in the rents and royalties category and cannot offset wages. Schedule NJ-BUS-2 allows netting across four business categories at 50 percent with a 20-year carryforward, and salary is not among them.

Depreciation recapture is the other half of the picture. Everything you accelerate comes back as ordinary income when you sell, so a study is a timing decision on real estate investments rather than a permanent reduction.

So when you run the arithmetic above, use your federal marginal rate for the benefit and treat the New Jersey saving as small. A provider showing you a blended federal-and-state number for a New Jersey property is showing you a number New Jersey does not allow.