The hobby loss rules in Section 183 of the Internal Revenue Code decide whether the IRS treats your side activity as a business or as a hobby, and the classification controls what you can deduct. If your activity is a hobby, you owe tax on every dollar of income it produces, and starting in 2026 you can deduct expenses only up to 90% of that gross income, and only if you itemize on Schedule A. The rules apply to individuals, partnerships, estates, trusts, and S corporations.1Internal Revenue Service. Is Your Hobby a For-Profit Endeavor?
How the IRS Decides Whether Your Activity Is a Hobby
The question turns on your objective intent: did you genuinely enter the activity to make money? You don’t need a reasonable expectation of profit, but you do need an actual profit objective backed by how you behave.2eCFR. 26 CFR 1.183-2 – Activity Not Engaged in for Profit Defined No single factor decides it. Treasury regulations list nine that normally come into play:
- Whether you run the activity in a businesslike way, with proper books, a separate bank account, and adjustments when something isn’t working.
- Your expertise, or your reliance on advisors with expertise.
- The time and effort you put in, including hiring qualified staff to run daily operations.
- Whether the assets used in the activity are expected to appreciate enough to produce an overall gain.
- Your track record turning around similar activities in the past.
- Your history of income and losses in this activity, with allowance for startup years and events outside your control.
- The size and frequency of any profits you have earned.
- Your financial status, since substantial outside income that hobby losses conveniently offset draws more scrutiny.
- Whether the activity involves personal pleasure or recreation.2eCFR. 26 CFR 1.183-2 – Activity Not Engaged in for Profit Defined
The list isn’t exclusive, and it isn’t a scorecard. Five factors in your favor and four against doesn’t automatically mean you win. In practice, the first (running the activity in a businesslike manner) and the last (personal pleasure) tend to carry the most weight, because they’re the hardest to fake.
The Three-Out-of-Five Profit Presumption
Section 183(d) gives you an objective safe harbor. If your activity shows a profit in at least three of five consecutive tax years ending with the current year, the law presumes you’re in it for profit. The IRS can still challenge you, but now the burden is on the IRS to prove you lack a profit motive rather than on you to prove you have one.3Office of the Law Revision Counsel. 26 USC 183 – Activities Not Engaged in for Profit
The Horse Activity Exception
Activities that primarily involve breeding, training, showing, or racing horses get a longer runway. The presumption applies if the activity shows a profit in at least two of seven consecutive tax years.1Internal Revenue Service. Is Your Hobby a For-Profit Endeavor?
Postponing the Determination With Form 5213
If your activity is too new to have hit the presumption window, Form 5213 lets you elect to postpone the IRS’s determination until you’ve completed it. For most activities, the IRS holds off until after the close of the fourth tax year following the year you started. For horse activities, the postponement runs through the sixth tax year after the starting year.4Internal Revenue Service. Form 5213 – Election to Postpone Determination as to Whether the Presumption Applies That an Activity Is Engaged in for Profit
You must file Form 5213 within three years after the due date (without extensions) of your return for the first tax year of the activity. If the IRS sends you a written notice proposing to disallow your deductions before that three-year window closes, you have 60 days from receiving the notice to file. The 60-day deadline is a secondary trigger, not an extension of the three-year period.4Internal Revenue Service. Form 5213 – Election to Postpone Determination as to Whether the Presumption Applies That an Activity Is Engaged in for Profit Filing has a real trade-off: the extra time comes at the cost of flagging for the IRS that you’re running an activity with current losses. Some advisors recommend against it and prefer to take deductions and defend them on the nine-factor test if challenged.
What You Can Actually Deduct Now
The practical effect of hobby classification has changed twice in recent years, so the year you’re filing for matters.
Before 2018, hobby expenses beyond a small first tier were miscellaneous itemized deductions on Schedule A, subject to a 2% of adjusted gross income floor. The Tax Cuts and Jobs Act then suspended all miscellaneous itemized deductions subject to the 2% floor from 2018 through 2025. For those eight years, hobby expenses were effectively non-deductible, and you owed tax on the full hobby income with almost no offset.
The One Big Beautiful Bill Act, signed in 2025, permanently eliminates the general category of miscellaneous itemized deductions subject to the 2% floor. It also created a specific rule for hobby expenses starting in 2026: you can deduct hobby expenses up to 90% of your hobby gross income. The deductible portion goes on Schedule A as a miscellaneous itemized deduction not subject to the 2% floor.
Two consequences follow from that structure. First, 10% of your hobby gross income is always taxable, even if your expenses exceed your income. Second, if you take the standard deduction rather than itemizing, you get no hobby deduction at all and still owe tax on the full hobby income. For taxpayers with modest hobby income, the standard deduction often wins on the math, which means the hobby expenses produce no tax benefit in practice.
How to Report Hobby Income and Expenses
Hobby income goes on Schedule 1 (Form 1040), line 8j, as other income. You report the full amount, with no netting of expenses beforehand.5Taxpayer Advocate Service. Hobby vs. Business Income This is different from a business, where net income or loss would go on Schedule C. Allowable expenses under the 90% cap go on Schedule A.
Hobby Losses Don’t Carry Forward
When an activity fails the Section 183 test, the hobby loss limitation applies before the passive activity loss rules of Section 469 come into play.3Office of the Law Revision Counsel. 26 USC 183 – Activities Not Engaged in for Profit You can’t treat disallowed hobby losses as passive losses and bank them against future passive income. Once the activity is classified as a hobby, the disallowed amount is gone permanently. It doesn’t carry forward under Section 469 or any other provision.
In numbers: if a hobby earns $10,000 of income and generates $15,000 of expenses, you report $10,000 in income and deduct up to $9,000 (90% of $10,000). The remaining $6,000 is permanently non-deductible. It can’t offset your wages, investment income, or passive income from anything else.
Accuracy Penalties and How to Protect Yourself
Claiming full business deductions for what the IRS later reclassifies as a hobby produces more than just extra tax. Under Section 6662, the IRS can add a 20% accuracy-related penalty on the resulting underpayment if it finds negligence or disregard of the rules.6Internal Revenue Service. Accuracy-Related Penalty On a $5,000 underpayment, that adds $1,000 on top of the tax, with interest running from the original due date.
Documentation is the best defense against both reclassification and penalties. Keep records tied to the nine factors: a written business plan, separate financial accounts, logs of time spent, evidence of expert consultations, and a paper trail showing you adapted your approach when results weren’t good enough. Taxpayers who lose hobby loss cases almost always share the same weakness: they couldn’t produce records showing they ran the activity like someone who actually intended to make money.