S Corporation Basis and AAA Mechanics

Stock basis starts with the shareholder’s tax investment in stock and changes with contributions, pass-through items and distributions. Debt basis generally requires bona fide indebtedness running directly from the corporation to the shareholder. A shareholder guarantee of a bank loan does not by itself create debt basis; actual payment under the guarantee can change the analysis. Corporate borrowing is not treated like a partnership liability allocation.

Both stock and qualifying debt basis can support a loss deduction at the basis stage, but only stock basis shelters an ordinary nondividend distribution. The distinction matters when a shareholder has little stock basis and a large direct loan. Repayment of debt whose basis was reduced by losses can also have tax consequences. A single combined “investment” total hides which transaction can use which basis.

Generally increase stock basis for income, including tax-exempt income, then reduce it for nondividend distributions, then nondeductible noncapital expenses and certain depletion items, then losses and deductions. An election can change the ordering of certain nondeductible expenses and losses, so preserve the assumptions in a question. Stock basis cannot fall below zero; qualifying debt basis can then support losses to the extent available.

A distribution made in a loss year can consume stock basis before the losses are applied. That does not automatically make the distribution taxable if sufficient stock basis existed under the ordering rule, but it can suspend more loss. After the basis limit, apply at-risk and passive-activity rules as relevant. The K-1 amount alone does not demonstrate a deductible loss or establish the shareholder’s basis history.

The accumulated adjustments account generally tracks accumulated undistributed S corporation income for specified distribution purposes. It is not a shareholder’s stock basis, cash account or retained earnings under financial accounting. Tax-exempt income generally increases stock basis but not AAA. AAA can become negative through applicable loss adjustments; a distribution does not reduce AAA below zero.

When accumulated C corporation earnings and profits exist, distribution ordering can involve AAA, dividend treatment from E&P and other layers, with elections capable of changing the order. Determine whether E&P exists before using the simplified no-E&P stock-basis rule. The Schedule M-2 instructions also require special ordering for a net negative adjustment, so do not assume every AAA computation follows the same sequence as shareholder stock basis.