S Corp Shareholder Basis, AAA, and Form 7203
The running number that decides whether your distributions are tax-free and whether you can deduct a loss.
Reviewed by the Fairlight Accounting cross-border tax team — U.S. & Canadian Tax Desks
Shareholder basis is a running measure of an S corporation owner's investment: what you put in, plus income passed through to you, minus distributions and losses. It decides whether distributions are tax-free and whether you can deduct a loss. You track it yourself, and the IRS requires Form 7203 whenever basis matters.
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Why is basis your job, not the corporation's?
The corporation reports your share of income, losses, and distributions on Schedule K-1, but it does not certify your basis. The shareholder is responsible for computing it. When you deduct a loss or take a distribution without knowing your basis, you risk an IRS adjustment years later, when the records are hardest to reconstruct.
How does stock basis change each year?
Basis is adjusted in a set order:
| Step | Adjustment | Direction |
|---|---|---|
| 1 | Starting basis (contributions and purchase price, or prior year's ending basis) | — |
| 2 | Income items, including tax-exempt income | Increase |
| 3 | Non-dividend distributions | Decrease (not below zero) |
| 4 | Nondeductible, non-capital expenses (for example, the disallowed half of meals and penalties) | Decrease (not below zero) |
| 5 | Losses and deductions | Decrease (not below zero) |
Because distributions come off before losses, a year with both can leave a loss suspended even when the business had cash to distribute. A shareholder can elect under Treas. Reg. §1.1367-1(g) to take losses before nondeductible expenses, carrying unused nondeductible expenses forward.
What is debt basis?
If you lend money directly to the corporation, you have debt basis equal to the loan balance. Losses that exceed stock basis can be deducted against debt basis, but distributions never reduce debt basis. Guaranteeing or co-signing a bank loan to the corporation does not create debt basis unless and until you make payments under the guarantee — only money you actually lend or pay counts. When the corporation later repays a loan whose basis was reduced by losses, part of the repayment is taxable.
What happens when basis runs out?
- Distributions above basis are taxed as capital gain.
- Losses above basis are suspended and carry forward indefinitely until you have basis to absorb them.
- After basis, losses still face the at-risk rules, the passive activity rules, and the excess business loss limit, in that order.
Where does AAA fit in?
The accumulated adjustments account (AAA) is a corporate-level account that tracks earnings taxed to shareholders while the company was an S corporation. It matters mainly for companies that were once C corporations and still hold earnings from those years. Distributions come first from AAA (tax-free to the extent of basis), then from old C corporation earnings (taxable as dividends), then from remaining basis. A company that has always been an S corporation can generally ignore the dividend layer.
When must Form 7203 be filed?
Attach Form 7203 to your Form 1040 if you:
- claim a deduction for your share of an aggregate loss from the S corporation (including a loss carried over from a prior year because of basis limits),
- receive a non-dividend distribution,
- dispose of stock, whether or not you have a gain, or
- receive a loan repayment from the corporation.
The IRS suggests completing the form even in years it is not required, so basis is maintained consistently.
Frequently asked questions
I never tracked basis. Can I reconstruct it?
Yes. Start from the first year — contributions or purchase price — and roll forward each year's K-1 items in the ordering above. Bank records and old returns fill most gaps. It is tedious but usually achievable.
Do my personal loans to the business count if they went through my LLC?
Generally no. Debt basis requires a direct loan from the shareholder to the S corporation. Loans from a related entity usually do not count unless restructured.
Are distributions ever taxable even with a profitable year?
Yes, if your basis was already exhausted from prior losses or distributions, or if the company has old C corporation earnings and AAA is depleted.
Does basis matter when I sell the company?
Yes. Your stock basis determines the gain or loss on a stock sale. An understated basis overstates your gain.
Official sources
The IRS explains: “Use Form 7203 to figure potential limitations of your share of the S corporation's deductions, credits, and other items that can be deducted on your return.” — Internal Revenue Service, Instructions for Form 7203 (12/2022), https://www.irs.gov/instructions/i7203
The IRS explains: “The accumulated adjustments account (AAA) is an account of the S corporation that generally reflects the accumulated undistributed net income of the corporation for the corporation’s post-1982 years.” — Internal Revenue Service, Instructions for Form 1120-S (2025), https://www.irs.gov/instructions/i1120s
Next step
Fairlight Accounting handles U.S. domestic, cross-border (U.S.–Canada), and international tax returns, plus bookkeeping, payroll, and CFO advisory. Our U.S. Tax Desk rebuilds shareholder basis schedules and prepares Form 7203 with each return. See pricing or book a free fit call.
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