S corporation basis rules: why losses need basis but credits do not

Every S corporation shareholder runs two ledgers: stock basis and debt basis. Together they answer three questions — whether passed-through losses are deductible now or suspended, whether distributions are tax-free returns of capital or capital gain, and what gain arises when the stock is sold. One thing they do not control: credits. The research credit and other general business credits pass through and are usable with zero basis, because Section 1366(d)'s limitation applies only to losses and deductions.

The annual ordering, and why it matters

Section 1367 adjusts stock basis every year in a fixed sequence: (1) up for income items, including tax-exempt income; (2) down for distributions; (3) down for nondeductible, noncapital expenses; (4) down for losses and deductions. Distributions beating losses in the queue is the practical headline. A shareholder with $50,000 of beginning basis in a year with a $60,000 pass-through loss and a $40,000 distribution takes the distribution tax-free (basis drops to $10,000), deducts $10,000 of loss, and suspends $50,000 under Section 1366(d)(2) — carried forward indefinitely, but only for that shareholder while she holds the stock. Suspended losses do not transfer with gifted or sold shares.

Distributions in excess of stock basis are capital gain, not a loan against the future. And shareholders — not the corporation — are responsible for tracking basis; Form 7203 now forces the computation onto the individual return whenever losses, distributions, or stock dispositions occur. Statutory text is at Sections 1366–1368 of the Internal Revenue Code; the ordering regulation is Treas. Reg. §1.1367-1 at eCFR Title 26.

Debt basis: only real loans count

Debt basis exists only for bona fide indebtedness from the corporation directly to the shareholder (Treas. Reg. §1.1366-2). A personal guarantee of the company's bank line creates nothing until the shareholder pays. Once losses have absorbed stock basis, they absorb debt basis; later income restores debt basis first. Repayment of basis-reduced debt triggers income — ordinary for open account debt, capital gain for a note — a trap with enough moving parts that we give it its own brief: shareholder loans to S corporations. Partnerships work differently: entity debt allocates into partner basis under Section 752, one of the structural reasons leveraged businesses often prefer partnership form, per the S corporation complete guide.

Credits ride free — mostly

The pass-through of credits is basis-blind. A startup S corporation generating research credits while burning cash can hand shareholders usable credits even as its losses pile up in suspense. The distinction across pass-through items looks like this:

"Mostly" free: the shareholder's own general business credit limitation, passive activity credit rules for non-material participants, and the pass-through mechanics covered here still apply. And one indirect basis interaction is easy to miss — if the corporation elects the full credit without the Section 280C reduced-credit election, the required expense disallowance is a nondeductible item that reduces basis at step three. A credit that needs no basis can still consume some.

Where shareholders get it wrong

The recurring failures: no basis records at all until an exam or a sale forces reconstruction; deducting losses against guaranteed-but-unpaid debt; and treating distributions as safe because "the company has retained earnings" — AAA is the corporation's ledger, basis is the shareholder's, and only basis protects a distribution. Reconstructing fifteen years of basis from K-1s is billable archaeology. Keep the schedule current from year one.