S corp losses are only deductible up to your basis, and distributions beyond basis become capital gain. How basis works, when Form 7203 is required, and how to track it.
Your S corporation lost money this year, your K-1 shows the loss — and your tax software just told you that you can't deduct it. The gatekeeper is basis: you can only deduct S corp losses up to your investment in the company, tracked on Form 7203. Losses beyond basis aren't gone, but they're suspended — locked until you put more in or the company turns profitable. And basis cuts the other way too: pull out distributions beyond your basis and the excess is taxed as capital gain, a surprise that shows up years after the sloppy bookkeeping that caused it.
Basis is the least glamorous number in S corp life and one of the most consequential. This post covers what basis is, how the loss limitation and the distribution trap work, when Form 7203 is actually required, and why stock basis and debt basis are different animals. It's the bookkeeping counterpart to getting reasonable salary right — one governs how money goes out as wages, the other governs everything else.
Basis is a running tally of your skin in the game. It starts with what you put in and moves every year with the company's results:
So: basis = money in + income − distributions − losses, compounding year over year. Say you started the company with $20,000, it earned $50,000 its first year, and you took $40,000 in distributions. Your stock basis is $20,000 + $50,000 − $40,000 = $30,000 going into year two. Basis can never go below zero — and the two big S corp traps live at that floor.
Your share of the company's loss is deductible only up to your basis. Continue the example: in year two the company loses $45,000. Your basis is $30,000, so you deduct $30,000 this year — the remaining $15,000 is suspended. Suspended losses aren't lost; they carry forward indefinitely and release when you rebuild basis, by contributing capital, lending the company money directly, or having a profitable year.
This is why a big early-years loss doesn't always deliver the refund people expect, and why a year-end capital contribution can be a live planning move: put $15,000 in before December 31 and the whole loss deducts now instead of waiting. (Basis is the first gate, not the only one — at-risk and passive-activity rules can also apply — but for active owner-operators, basis is usually the one that bites.) Note also that losses only exist to absorb if the company actually runs at a loss; owners still finding their footing in year one should also read up on estimated taxes in your first S corp year, since a profitable first year creates the opposite problem.
The mirror-image rule: distributions are tax-free only up to your stock basis. Take out more than your basis and the excess is taxed as capital gain — as if you'd sold a slice of stock you didn't own. This is the classic S corp ambush: the company had a weak year, but you kept your usual monthly draws going, and in March your preparer tells you $18,000 of what you thought was tax-free cash is a taxable gain.
The full mechanics of when distributions are and aren't taxable — including the salary-first requirement and multi-shareholder timing — are covered in our guide to S corp distribution tax rules. The takeaway for this post: you cannot know whether a distribution is tax-free without knowing your basis, which is exactly why the IRS built a form to force the issue.
Form 7203 (S Corporation Shareholder Stock and Debt Basis Limitations) attaches to your personal return. You must file it for any year in which you:
Read that list again: almost every active owner-operator takes distributions, which means for most S corp owners Form 7203 is effectively an every-year form. It walks through the basis arithmetic in order — increases first, then distributions, then nondeductible items, then losses — and forces you to show the number that determines whether your losses deduct and your distributions stay tax-free.
Form 7203 tracks two separate pools, and the distinction matters when losses exceed stock basis:
The rule everyone gets wrong: guaranteeing the company's bank loan gives you nothing. Basis requires an actual economic outlay from you to the corporation. Co-signing the line of credit, personally guaranteeing the SBA loan, pledging your house — none of it creates debt basis until you actually pay on the guarantee. If the company needs money and you need basis, the clean structure is: you borrow personally, then you lend to the corporation. Same cash, completely different tax result.
Debt basis has its own trap, too: when losses have eaten into your debt basis and the company later repays your loan, part of that repayment is taxable income to you. Loan repayments are one of the Form 7203 triggers for exactly this reason.
Guarantees don't create basis. Only money that actually leaves your pocket for the corporation — as capital or as a direct loan — counts.
Here's the practical problem: the IRS puts the burden of tracking basis on you, the shareholder — not the corporation. Your K-1 reports income, losses, and distributions, but it does not report your basis. If you've never tracked it, nobody has.
Reconstructing a decade of basis means pulling every K-1 and capital contribution back to day one and rebuilding the tally year by year — expensive when a professional does it, unreliable when done from memory, and urgent at the worst times: the year you want to deduct a big loss, take a big distribution, or sell the company. The alternative costs fifteen minutes a year: update the schedule every spring when the K-1 arrives. Start from last year's ending basis, add income and contributions, subtract distributions and losses, done. Keep it in the same folder as the return.
Basis is money in plus income, minus distributions and losses. Losses deduct only up to basis; distributions beyond basis become capital gain; Form 7203 is how you prove the number — and for anyone taking distributions, that means annually. Track it every year while the records are fresh, and remember that only direct loans, never guarantees, create debt basis. Taxagon's CPAs and EAs prepare Form 7203, maintain basis schedules, and reconstruct the messy ones as part of business tax filing — if you've been running an S corp for years and have never seen your basis number, reach out before it matters.
This article is general information, not tax advice for your specific situation. Tax law changes; figures are for the years stated.
Talk it through with a licensed US tax professional — we'll tell you honestly whether it applies to your situation.
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