The 2026 Excess Business Loss Cap Got Smaller

TLDR

The One Big Beautiful Bill Act (OBBBA) made the IRC §461(l) excess business loss cap permanent, so it will not expire the way it was scheduled to. But OBBBA also changed HOW the cap is adjusted for inflation each year, and the new method resets the starting point. The result for 2026 is a cap of $256,000 for single filers and

$512,000 for married filing jointly

, lower than what plain inflation indexing from 2025 would have produced. §461(l) is the LAST gate a business loss passes through, after basis, at-risk, and passive activity rules. A loss that clears all three of those gates can still get capped here. The capped amount is not lost. It becomes a net operating loss (NOL) carryforward you can use in future years, subject to its own limits.

In this guide, you’ll learn:

Why the 2026 excess business loss cap is lower than 2025’s, even though OBBBA made the rule permanent
Where §461(l) sits in the sequence of loss limitations, and why it comes after basis, at-risk, and passive rules, not instead of them
The practitioner trap: why your own S-corp salary does not help you absorb a large K-1 loss under this rule
A full worked example of a shareholder with a big loss, showing exactly what’s deductible now and what carries forward
What happens to the disallowed amount once it becomes an NOL carryforward

#Where this cap fits in the loss-limitation lineup

If you own a piece of an S-corp, a partnership, or a sole proprietorship, your loss doesn’t go straight from the K-1 to your Form 1040. It has to clear a sequence of checkpoints first. Our guide on S-corp loss limitations: basis, at-risk, and passive rules covers the first three gates in detail:

Basis (IRC §1366(d)): can’t deduct more loss than you’ve put into the company
At-risk (IRC §465): can’t deduct more than you’re personally exposed to lose
Passive activity (IRC §469): can’t deduct a loss from a business you don’t materially participate in against your ordinary income

This article picks up where that one stops. IRC §461(l), the excess business loss limitation, is a fourth gate that sits after all three of the above. It’s a completely different mechanism from the passive activity loss rules, even though the two get confused constantly. Passive loss rules (§469) ask: “Do you materially participate in this specific activity?” The excess business loss rule (§461(l)) asks a much bigger question: “Across every active trade or business you’re involved in, added together, how much net loss did you generate this year, and does it exceed a flat dollar threshold?”

That second question applies even to a loss that already passed the passive activity test. If you work full-time in your S-corp, materially participate, and have plenty of basis and at-risk amount, your loss sails through gates one through three. §461(l) is the one gate that can still stop it, purely because of the dollar amount involved.

#Why the 2026 threshold is lower, even though the rule is now permanent

Before OBBBA, §461(l) was scheduled to sunset. Congress had already extended it once, and without further action it was set to expire after the 2028 tax year. OBBBA removed that expiration date entirely. The excess business loss limitation is now a permanent part of the code, not a temporary rule that needs periodic renewal.

That part is good news for predictability. What surprises people is the second change OBBBA made in the same provision: it reset the base year used to calculate the annual inflation adjustment. Before OBBBA, the threshold amounts were indexed off a 2018 base year. OBBBA moved that base year forward to 2025. Practically, this rolled the dollar thresholds back down closer to where they started under the original 2018 rule, erasing several years of inflation increases in one step.

The result is a threshold that moves in the opposite direction most taxpayers expect. Usually when a number is “indexed for inflation,” it goes up every year. Here, the 2026 threshold is a step down from where 2025 left off, because the starting point for the math changed, not because inflation reversed.

$256,000

2026 threshold, single filers

Rev. Proc. 2025-32 §4.31
$512,000

2026 threshold, married filing jointly

Rev. Proc. 2025-32 §4.31

IRS Rev. Proc. 2025-32, published under the OBBBA-amended IRC §461(l)(3)(C) inflation methodology.

For 2025, the thresholds were $313,000 for single filers and $626,000 for married filing jointly. So a married couple who could absorb $626,000 of net business loss against their other income in 2025 can only absorb $512,000 in 2026, a drop of $114,000, even though nothing about their business changed. That’s the headline: a shareholder whose loss was fully deductible under this rule last year could see part of the same-sized loss capped this year, purely because the threshold moved.

#What counts as business income for this calculation, and the W-2 wage trap

§461(l) works by netting your total business deductions against your total business income and gains, then comparing the shortfall to the threshold. Anything beyond the threshold is the excess business loss.

The genuinely counterintuitive part: your own W-2 wages from the S-corp you work for are not counted as business income for this calculation, even though you materially participate in that same business and the wages are your reasonable compensation. Wage income is treated as nonbusiness income here. It gets backed out before the business income and business loss sides of the equation are compared. This is a well-documented practitioner trap, not an edge case: an S-corp owner who pays themselves a healthy salary might assume that salary “offsets” the loss for this purpose. It doesn’t. Only actual trade-or-business income and gains count on the business side of the ledger.

This is genuinely counterintuitive because it cuts against how basis and at-risk work. Those two gates care about what you put into the business. §461(l) cares about your total net business results for the year against a flat dollar line, and wages you draw from your own company don’t move that line.

#Worked example: a shareholder with a large K-1 loss

Priya owns 100% of an S-corp that had a rough year. The business generated a $580,000 ordinary loss on the K-1, driven by a large equipment purchase written off under bonus depreciation. Priya is married and files jointly with her spouse, Raj, who has W-2 income of $140,000.

Priya draws a $90,000 reasonable-compensation salary from the S-corp as a W-2 employee. She works full-time in the business and clearly materially participates.

Step 1: Basis and at-risk. Priya contributed enough capital and has enough debt basis to fully absorb the $580,000 loss, and her at-risk amount is equally sufficient. Gates one and two clear with no suspension.

Step 2: Passive activity. Priya materially participates (well over 500 hours). Gate three clears. The full $580,000 is a non-passive, currently deductible loss as far as §469 is concerned.

Step 3: Excess business loss, §461(l). This is where the math changes. Priya and Raj’s business income and gains for the year: none, since the S-corp had a loss and neither of them has other trade-or-business income. Priya’s $90,000 salary and Raj’s $140,000 salary are both nonbusiness (wage) income and don’t count as business income here. So the calculation nets $580,000 of business deductions against $0 of business income and gains, a net business loss of $580,000, before the threshold is applied.

2026 threshold, married filing jointly: $512,000
Net business loss: $580,000
Deductible this year: $512,000
Disallowed and carried forward as an NOL: $580,000 minus $512,000 = $68,000

Priya and Raj deduct $512,000 of the loss against their 2026 income (their wages, interest, and any other income), and the remaining $68,000 does not disappear. It converts into a net operating loss carryforward, available starting in 2027, subject to the 80%-of-taxable-income NOL limitation described below.

If Priya were single instead of married filing jointly, the calculus changes sharply. Her 2026 threshold would be $256,000, so she’d deduct $256,000 this year and carry forward $580,000 minus $256,000, or $324,000, as an NOL. Filing status changes the outcome by hundreds of thousands of dollars in this scenario, which is exactly why the threshold has to be checked against the correct filing status every year, not assumed from memory.

#What happens to the disallowed amount

The excess business loss that gets capped in the current year is not a lost deduction. IRC §461(l)(2) converts it into a net operating loss (NOL) carryforward, treated the same as any other NOL for the following tax year.

Two rules then govern how that carryforward gets used:

It carries forward indefinitely. Under current law, NOLs generated in tax years after 2017 do not expire. There’s no 20-year clock running on this carryforward the way there was under pre-2018 rules.
It’s capped at 80% of taxable income in any future year. This limits how much INCOME the loss can wipe out, not your final tax bill, which credits and other rules can still reduce further. An NOL carryforward, including one that originated as a disallowed excess business loss, can only offset up to 80% of your taxable income in the year you use it, computed before the NOL deduction itself. So a large carryforward cannot wipe out all of your taxable income in one shot, even in a year with plenty of income to absorb it.

So the practical effect of hitting the §461(l) cap is a timing problem, not a permanent loss of the deduction. The loss moves from “this year” to “future years, spread out by the 80% rule,” which has real cash-flow consequences even though the dollars aren’t gone for good.

#Common questions

Does the excess business loss limitation apply to every S-corp shareholder? It applies to noncorporate taxpayers, which includes individuals (S-corp shareholders, partners, and sole proprietors), trusts, and estates that aren’t themselves taxed as C-corporations. It does not apply at the entity level. Each shareholder or partner computes their own §461(l) calculation on their personal Form 461, based on their own share of business income and loss from all the activities they’re involved in, not just one entity.

If I materially participate in my S-corp and passed the passive activity test, why would my loss still get capped? Because §461(l) is a completely separate rule from the passive activity loss test in §469. Passing the passive activity test only means the loss isn’t blocked by that specific gate. The excess business loss rule is a dollar-threshold rule that applies on top of, and after, the passive activity test, regardless of how actively you participate.

Does my S-corp salary help offset a large K-1 loss for this calculation? No, and this one catches people out. Wages, including reasonable compensation you pay yourself as an S-corp employee, are treated as nonbusiness income for the §461(l) calculation and don’t add to your loss-absorption capacity. Only actual trade-or-business income and gains count on the business side.

Is the 2026 threshold really lower than 2025’s? Yes. For 2025 the thresholds were $313,000 single and $626,000 married filing jointly. For 2026, under the OBBBA-amended inflation methodology, they’re $256,000 single and $512,000 married filing jointly. That’s a real decrease, not a typo, and it’s driven by OBBBA resetting the inflation base year rather than by any change in the underlying economics.

Does this rule expire again in a few years, like it was scheduled to before? No. OBBBA made §461(l) permanent. There’s no scheduled sunset anymore. What changes year to year now is only the inflation-adjusted dollar threshold, published annually by the IRS (currently Rev. Proc. 2025-32 for 2026), not whether the rule itself is still in effect.

What form do I actually file for this? Form 461, Limitation on Business Losses, attaches to your personal return in any year your aggregate business losses (after basis, at-risk, and passive limitations) exceed the applicable threshold. If you’re not sure whether your loss year triggers this, it’s worth running the calculation before you file rather than assuming a large K-1 loss automatically flows through in full.

Can married filing separately use half the joint threshold? Rev. Proc. 2025-32 §4.31 states a single base amount with one carve-out: $256,000, and $512,000 for joint returns. A separate return is not a joint return, so a married-filing-separately taxpayer uses the $256,000 figure, not half of the joint amount. Because filing separately changes far more than this one threshold, run the whole return both ways before choosing, rather than assuming a simple half-of-joint split.

#Want your K-1 loss run through all four gates before you file?

A big loss year is exactly when the sequencing matters most: basis, at-risk, passive activity, and now the excess business loss threshold, each one capable of stopping part of your deduction on its own. We’ll walk through where your loss actually lands, what’s deductible this year, and what turns into an NOL carryforward you can plan around.

Book a 15-minute Tax Discovery, Google Meet, no pitch, free advice either way.

If the loss is tied to a bigger structural question, like whether your entity choice still makes sense, our tax planning advisory service works through the full picture.