Real Estate Tax Calc
The passive loss problem
Rental activities are generally classified as passive under the Internal Revenue Code regardless of how much time you spend on them (with narrow exceptions). Passive losses can only offset passive income — not wages, self-employment income, or portfolio income such as dividends and interest. If a cost segregation study creates a $200,000 paper loss and you have no other passive income, that loss is suspended and carried forward until you generate passive income or sell the property.
Three ways to use the losses currently
(1) Real Estate Professional Status (REPS): spend more than 750 hours per year in real property trades and more than half your total working hours in real estate, and materially participate in each property. Losses then offset any income, including wages. (2) Short-term rental exception: if the property has an average rental period of 7 days or fewer and you materially participate, it is not a rental activity for PAL purposes, and losses may offset ordinary income without REPS. (3) Other passive income: cost seg losses offset income from passive investments such as limited partnerships.
The suspended loss silver lining
Suspended passive losses are not gone — they accumulate tax-free and release entirely in the year you sell the property. In that year, they offset all income including the gain from the sale. This makes cost segregation worth considering even if you cannot use the current losses: you are building a tax shield for your exit. The trade-off is timing — you may wait years before accessing the benefit.
A worked example: the $200,000 paper loss
Suppose you buy a $1,000,000 rental (say $800,000 building, $200,000 land), commission a cost segregation study that reclassifies $250,000 into 5-, 7-, and 15-year property, and — with bonus depreciation in play — write off roughly $200,000 in year one on top of regular depreciation. Your Schedule E shows a $180,000 net loss after rent and operating expenses. If you are a passive investor with a $300,000 W-2 salary and no passive income, none of that $180,000 offsets your wages. It suspends on Form 8582 and carries forward. If instead you or your spouse qualify as a real estate professional and materially participate, the same $180,000 loss offsets the salary directly — worth about $66,600 in federal tax at a 37% marginal rate. The paper loss is identical; the tax result swings entirely on your participation status. That is why status planning, not the study itself, is where the real money is made or lost.
The $25,000 special allowance for active participation
There is a middle tier between fully passive and real estate professional. Under IRC Section 469(i), a taxpayer who actively participates in a rental — a lower bar than material participation, generally meaning you make management decisions such as approving tenants, setting rents, and authorizing repairs — may deduct up to $25,000 of rental losses against ordinary income each year. But this allowance phases out as your modified adjusted gross income rises: it drops by 50 cents for every dollar of MAGI over $100,000 and disappears entirely at $150,000 MAGI ($75,000/$100,000 if married filing separately and living apart). Because a cost segregation study on most properties produces a loss far larger than $25,000, and because investors with the income to buy such properties are frequently above the $150,000 phase-out ceiling, this allowance often provides little relief for cost-seg-sized losses — but it can still absorb a slice for a moderate-income landlord.
Real estate professional status, in detail
REPS is defined in Section 469(c)(7). To qualify for a year you must satisfy two quantitative tests: (1) more than 750 hours of service in real property trades or businesses in which you materially participate, and (2) more than half of all the personal service hours you work in any trade or business must be in real property trades or businesses. A full-time W-2 employee generally cannot meet the second test because the 2,000-plus hours at their job dwarf their real estate hours. On a joint return, either spouse can meet the tests individually — you cannot combine the two spouses' hours to reach 750, though you can combine material-participation hours once one spouse qualifies. Qualifying as a real estate professional removes the per se passive label; you must then also materially participate in each rental (or elect to group them) for the losses to be non-passive. Keep a contemporaneous time log — the Tax Court routinely disallows REPS for lack of credible records.
The seven material-participation tests
Whether you are relying on REPS or the short-term rental exception, 'material participation' is defined by seven tests in Temporary Reg. Section 1.469-5T; meeting any one of them suffices. The three most commonly used are: participating more than 500 hours in the activity during the year; doing substantially all of the participation in the activity (common for a self-managed single rental); or participating more than 100 hours and more than any other individual, including a property manager. There are also tests for significant-participation activities, a five-of-ten-years test, a personal-service-activity test, and a facts-and-circumstances test. The hours must be real and documented — travel time and investor-type activities such as merely reviewing statements generally do not count.
The short-term rental exception, step by step
The most-used route to non-passive treatment without meeting the 750-hour REPS test is the short-term rental. Under Reg. Section 1.469-1T(e)(3)(ii), a rental whose average period of customer use is 7 days or fewer (or 30 days or fewer if you provide substantial personal services) is not a 'rental activity' for passive-loss purposes at all. It is treated as a trade or business, so the per se passive rule of Section 469(c)(2) simply does not apply. If you then materially participate — most owners of a self-managed short-term rental clear the 100-hour-and-more-than-anyone-else test or the substantially-all test — the loss is non-passive and can offset W-2 and other ordinary income with no REPS requirement. This is why cost segregation plus a self-managed Airbnb is such a popular pairing. Two cautions: compute the average stay correctly (total rental days divided by number of separate stays), and beware that heavy personal services can push the activity into self-employment territory.
How suspended losses finally release at sale
Under Section 469(g), when you dispose of your entire interest in a passive activity in a fully taxable transaction to an unrelated party, the activity's suspended losses are freed and become deductible against income of any kind — first against that activity's gain, then against other passive income, and then against non-passive income including wages. This is the exit that redeems a suspended cost-seg loss. Three traps: a 1031 exchange is not a fully taxable disposition, so it carries the suspended losses forward into the replacement rather than releasing them; a sale to a related party (as defined in Sections 267(b) and 707(b)) does not trigger the release; and an installment sale releases the suspended losses in proportion to the gain recognized each year. Plan the exit so the year the losses release is a year you can use them.
Even non-passive losses hit the excess business loss cap
Clearing the passive hurdle is not the last gate. Under Section 461(l), an excess business loss limitation caps how much net business loss a non-corporate taxpayer can use against non-business income in a single year. For 2025 the threshold is roughly $313,000 (single) or $626,000 (married filing jointly), indexed annually. So if your cost-seg study and material participation produce, say, a $500,000 non-passive loss and you are single, only about $313,000 of it can offset your wages and other non-business income this year; the excess becomes a net operating loss carried forward to future years. This rule (extended through 2028 under current law) is easy to forget when modeling a large first-year write-off — a giant loss does not always mean a giant same-year refund. Coordinate the size of the deduction with the income you actually have available to shelter.
State conformity is not guaranteed
Your federal loss is only half the story. Many states decouple from federal bonus depreciation — the very provision that makes cost segregation so powerful — and require you to add back the bonus deduction and depreciate those components on a slower state schedule. Some states also apply their own passive-loss and loss-limitation rules, or do not conform to Section 461(l). The practical effect is that a study can generate a large federal loss while your state return shows little or no loss the same year, with the state depreciation catching up over time. High-tax states are where this divergence bites hardest. Before assuming a study wipes out your state tax too, check your state's conformity to bonus depreciation and its passive-activity treatment, or ask your preparer to model both returns — the federal and state benefits can be years apart.
Frequently asked questions
Can cost segregation losses offset my W-2 income?
Only if you qualify as a real estate professional or the property is a short-term rental with material participation. Otherwise losses are passive and suspend until you have passive income or sell the property.
What happens to suspended passive losses when I sell?
They fully release in the year of sale and can offset all income in that year — including the recapture and capital gain from the sale itself.
What is the $25,000 rental loss allowance?
Under Section 469(i), a taxpayer who actively participates in a rental can deduct up to $25,000 of rental losses against ordinary income, but the allowance phases out between $100,000 and $150,000 of modified AGI and is gone above $150,000. It rarely covers a full cost-segregation loss.
Does the short-term rental exception require 750 hours?
No. The 750-hour test is for real estate professional status. The short-term rental exception (average stay of 7 days or fewer) only requires that you materially participate — often met by the 100-hour-and-more-than-anyone-else test — and it does not require REPS.
Do suspended losses release in a 1031 exchange?
No. A 1031 exchange is not a fully taxable disposition, so suspended passive losses carry forward into the replacement property rather than releasing. They release only on a fully taxable sale to an unrelated party.
Sources
Educational information and estimates only. Not tax advice. Tax rules change and vary by situation; consult a qualified tax professional before acting.