The Gambling Loss Deduction Just Dropped to 90% — And Break-Even Now Costs You

There is a particular kind of tax change that never makes the news because it does not raise a rate, does not remove a credit, and fits in a single sentence. It just alters an arithmetic operation somewhere deep in the code, and the consequences show up eleven months later on somebody's return.

The gambling loss deduction is now one of those. Beginning with tax year 2026 — the return most people will file in early 2027 — the deduction for wagering losses is capped at 90% of those losses rather than 100%.

Ten percent sounds small. What it actually does is remove the possibility of breaking even. Under the old arithmetic, a gambler who won and lost the same amount owed nothing on the activity. Under the new arithmetic, that same gambler has taxable income. Not income they received. Income the formula produces.

This is worth understanding whether or not you gamble, because the mechanism — tax on a number that does not correspond to money in your pocket — shows up in other corners of the code, and because sports betting and prediction markets have pulled a lot of people into a filing situation they have never had to think about before.

How the Old Math Worked

The starting point surprises people, and it predates this change entirely: you report gambling winnings gross, not net.

If you had a year with $60,000 in winning sessions and $58,000 in losing sessions, you do not report $2,000 of profit. You report $60,000 of income on the front of your return, and then — if you qualify — you claim $58,000 of losses as an itemized deduction on Schedule A.

Two constraints have always applied. First, losses were deductible only up to the amount of your winnings; you could never use a bad year at the casino to shelter your salary. Second, and this is the one that quietly disqualifies most casual players, you have to itemize. The standard deduction has been high enough since 2018 that the large majority of filers never itemize at all, which means for them gambling losses have effectively been non-deductible for years. They report the winnings and get nothing back for the losses.

So the population that actually used this deduction is narrower than you would guess: people with enough mortgage interest, state and local tax, and charitable giving to itemize anyway, plus people whose gambling volume alone is large enough to push them over the line.

What Actually Changed

The 2025 federal tax law amended the wagering loss rule in two ways, both effective for tax years beginning after December 31, 2025.

The 90% cap. Deductible wagering losses are now limited to 90% of the losses incurred during the year. The old ceiling — losses cannot exceed winnings — still applies on top. So the deduction is the lesser of two numbers: 90% of your losses, or the full amount of your winnings.

Expenses now count as losses. The law also made permanent the rule that expenses incurred in connection with wagering — travel, entry fees, subscriptions, the cost of getting to the table — are treated as part of your "losses" for this purpose rather than as separate business deductions. This matters almost entirely to professional gamblers, who used to be able to deduct those costs without running them through the §165(d) ceiling. Now those costs are inside the cap, and inside the 90% haircut too.

Put the 90% cap in the form that makes it legible: the code now assumes you kept ten cents of every dollar you lost. You did not. But that is the assumption you are taxed on.

The Worked Example: A Break-Even Year

Take a recreational sports bettor who itemizes. Over 2026 she places a lot of wagers. When the year closes, her session-by-session records show:

• Winning sessions totaling $100,000
• Losing sessions totaling $100,000
• Net economic result: zero. Her bank balance is exactly where it started.

Under the pre-2026 rules:

• Gambling income reported: $100,000
• Losses deducted: $100,000
• Net taxable gambling income: $0
• Federal tax on the activity: $0

Under the 2026 rules:

• Gambling income reported: $100,000
• Losses deducted: 90% of $100,000 = $90,000
• Net taxable gambling income: $10,000
• Federal tax at a 24% marginal rate: $2,400

She made nothing and owes $2,400. Scale it to a serious volume bettor — $1,000,000 through the book, break-even — and the phantom income is $100,000 and the bill is roughly $24,000 on zero profit.

It scales down too, and this is the part people miss. A modest bettor with $8,000 in winning sessions and $8,000 in losing sessions has $800 of phantom income, which at a 22% rate is about $176. Small, but it is $176 for having done something that made her nothing.

Here is the number I find most clarifying. Since your taxable gambling income is now (winnings − 0.9 × losses), you need your winnings to be less than 90% of your losses to owe nothing. In other words, you now have to lose roughly 11% more than you win before the activity becomes tax-free. Break-even is no longer the break-even point. Losing is.

And there is a second-order cost that does not show up in that arithmetic at all. Those gross winnings sit in your adjusted gross income before any deduction touches them. A six-figure gross winnings number can push you across thresholds that have nothing to do with gambling — Medicare premium surcharges, marketplace premium credits, education credits, the taxable portion of Social Security. Those phase-outs read the top-line number, not the net.

Who This Actually Affects

Ranked by how hard it lands.

Professional gamblers — hardest, by a wide margin. Poker players, advantage players, sharp sports bettors. These are people running six or seven figures of gross volume on thin margins, where a 10% disallowance on the loss side can exceed the entire year's actual edge. A player whose real return is 3% of handle can now owe tax that dwarfs the profit. Some of that population will find the arithmetic no longer works at all.

High-volume recreational bettors who itemize — hit meaningfully. The person running thousands of small wagers across a season. Gross numbers get large fast even when the net is trivial.

The occasional big winner — barely touched. One jackpot, no offsetting losses, no itemizing. Their tax situation is essentially unchanged; they were already paying on the full win.

Casual players who take the standard deduction — unchanged. They were already getting no benefit from their losses. You cannot reduce a deduction someone was not taking.

Then there is the state layer, which existed before this change and gets worse alongside it. A number of states tax gambling winnings as gross income while allowing no deduction for losses at all, either because the state has no itemized deductions or because it specifically disallows this one. In those states, a break-even gambler already had state tax on phantom income. The federal change now stacks on top.

Prediction Markets: The Unsettled Part

The timing here is what makes this more than a niche issue. Regulated event contracts — trading on outcomes in elections, economic releases, sports — have grown into a meaningful market, and they sit in a genuinely unresolved place in tax law.

The honest answer is that treatment is not settled, and I am not going to pretend otherwise. Two broadly different characterizations are in play. If an event contract is a wagering transaction, then §165(d) applies and so does the new 90% cap. If it is a regulated futures or derivative contract, a different regime applies — potentially with mark-to-market treatment and a blended long/short-term rate, and critically, without the wagering-loss ceiling at all. Losses in that world offset gains normally.

The difference between those two answers, for an active trader, is enormous. And it may well not resolve uniformly: the same platform can list contracts that look economically like a sports bet and contracts that look economically like an interest-rate derivative.

Two practical points. First, whatever tax form the platform issues you is the platform's characterization, not a ruling — and it is what the IRS will have received. Second, if you have material volume in event contracts, this is a genuine question for a tax professional, not one to resolve by reading a forum thread. I say that as someone who generally thinks people should learn to do their own taxes.

Records: More Important Now, Not Less

The tighter the deduction, the more it costs you to be sloppy about the number you are deducting 90% of. What you need:

A contemporaneous session log. Not a reconstruction in March. Date, location or platform, type of wager, amount in, amount out. The IRS has long expected a diary-style record, and the burden of substantiation is on you.

Session-level accounting, not wager-level. This is the single most valuable thing on this list and most people do not know it. For slot play the IRS has accepted netting within a session — you record the net result of a continuous period of play, not each individual spin. The difference is not cosmetic. Logged wager-by-wager, a day of play might show $9,000 of "winnings" and $8,700 of "losses." Logged as one session, it shows a $300 win. Under a 90% cap, inflated gross figures on both sides directly manufacture phantom income. Get the session boundaries right and a lot of the problem shrinks.

Every W-2G and 1099, matched to your log. Payers report certain wins directly to the IRS. Those reporting thresholds have been the subject of recent legislative attention, so check the current year's figures rather than assuming the ones you remember — but the principle is constant: some of your wins are already known to the government, and your return needs to be consistent with them.

Platform statements, downloaded and kept. Sportsbooks and exchanges provide annual summaries. Download them each January. Accounts get closed, apps get delisted, companies get acquired, and the year-end statement you did not save is not recoverable in an audit three years later.

The expense side, now that it counts. If you are filing as a professional, travel and entry fees now run through the same capped bucket. Track them with the same discipline.

None of this is exotic. It is a spreadsheet with six columns, updated the same evening. The reason it matters more in 2026 than it did in 2025 is that the penalty for a padded gross figure used to be zero — the losses cancelled the winnings exactly — and now every dollar of overstatement on both sides leaves ten cents of taxable residue behind.

Frequently Asked Questions

If I only bet a few hundred dollars a year, does this affect me? Almost certainly not, and probably not for the reason you think. If you take the standard deduction — as most filers do — you were never deducting gambling losses in the first place. The 90% cap reduces a deduction you were not claiming. You do still owe tax on your winnings, which has always been true and which a lot of casual bettors do not realize.

Can I net my wins and losses and just report the difference? No, and this is the most common and most expensive mistake in this area. Winnings go in gross on the income side; losses come out as an itemized deduction, now at 90%. Reporting only the net understates your income even when it produces a similar bottom line, and it will not match the W-2G data the IRS already has.

Does the 90% limit apply to state taxes too? It depends entirely on your state. Some states conform automatically to the federal definition, some conform selectively, and some never allowed a gambling loss deduction to begin with. Check your own state's rule — the combination of a state that disallows losses and the new federal cap is the worst version of this.

Is there any way around the cap? Not by structuring; the limit applies to the deduction itself. What genuinely changes your outcome is accurate session-level accounting, which lowers your gross figures on both sides legitimately. Beyond that, the honest answer for a professional is that the after-tax economics of the activity have changed and the response is to re-run the numbers, not to look for a workaround.

What if I gamble at a loss for the year? Then your deduction is capped at your winnings anyway, and the 90% limit may not bind — the deduction is the lesser of 90% of losses or total winnings. You still cannot deduct net gambling losses against other income. That has never been allowed and is not new.

The thing about a change like this is that it does not announce itself. Nobody gets a letter. The first time most people meet it will be a tax bill in the spring of 2027 on a year they remember as roughly a wash — and by then the records that could have made it smaller either exist or they don't.

This is general information about how a tax provision works, not tax advice for your situation. If you have meaningful gambling or event-contract volume, talk to a professional who can see your actual numbers.