Silence from your CPA about cost segregation is rarely negligence. It is usually some mix of practice economics, outdated assumptions, and a legitimate read of your tax situation. Sorting out which one applies to you is the useful move, because 1 of the 3 is fixable with a 10-minute screen.
Reason 1: compliance practices do not sell planning
A typical tax practice spends January through April producing returns and the rest of the year on extensions, notices, and bookkeeping cleanup. Cost segregation is a planning project: it needs a benefit model, coordination with an independent engineering firm, and often a Form 3115 with a section 481(a) catch-up computed under the automatic change procedures. None of that fits inside a compliance engagement priced by the form, so it tends not to come up unless the client raises it.
Reason 2: the old price assumptions
For years the rule of thumb was that engineering studies only made sense on large commercial property, and plenty of practitioners still carry that assumption. Study pricing and delivery have broadened since then, and bonus depreciation changed the payoff math: under OBBBA, qualified property acquired after January 19, 2025 gets permanent 100% bonus under IRC section 168(k), which front-loads the entire short-life reclassification into year 1. A $750,000 rental that was marginal under old assumptions can clear the hurdle today. A screen, not a rule of thumb, is how you find out.
Reason 3: your losses might have been unusable
This is the reason that is often correct. Rental losses are passive under section 469, and a W-2 earner with income over the phase-outs generally cannot deduct passive losses against wages. If that describes you, a big depreciation deduction just becomes a suspended loss, and a CPA who declined to sell you a study for suspended losses did you a favor. The calculus changes with real estate professional status under section 469(c)(7), or with a short-term rental averaging 7 days or less per stay under Reg 1.469-1T(e)(3) where you materially participate, because those losses escape the passive basket and can offset other income.
A worked example
An engineer earning $220,000 in W-2 wages owns a $600,000 long-term rental. A study would generate roughly a $100,000 first-year loss that section 469 suspends almost entirely: correctly, her CPA never pushed it. In 2026 she converts the property to a short-term rental with average stays under 7 days and logs material participation. Now the same loss is non-passive, and the study she skipped 3 years ago becomes a look-back captured through Form 3115 with a section 481(a) catch-up, no amended returns.
How to settle it with numbers
Amadae's cost segregation screen models the reclassification and first-year benefit for your specific property, and its free Tax Strategy Projector includes a short-term rental plus cost segregation dial, so you can see whether the loss is usable before anyone spends money. Amadae is not an engineering firm and does not perform studies; it screens, models, coordinates with the study firm, prepares the Form 3115 when a look-back applies, and files the return. If the screen says the strategy does not fit, that is also an answer, and it is the same one your CPA may have quietly reached years ago.