Built-In Gain

What is built-in gain?

Built-in gain is appreciation that existed in a C corporation's assets at the moment it converted to an S corporation. If the company sells those assets within a recognition period after conversion, the gain is taxed at the corporate level in addition to flowing through to shareholders. The rule exists to stop companies from converting simply to escape corporate tax on gains that accrued as a C corporation.

How it surfaces for service firms

Hard assets are not usually the issue. The trap is accounts receivable at a cash-basis firm. On conversion day, unbilled and uncollected receivables carry zero basis and substantial value, so collecting them within the recognition period can trigger built-in gains tax. The same applies to work in progress. Many firms convert without realizing their receivable balance is the asset the rule is aimed at.

Managing the recognition period

Get a valuation of assets as of the conversion date so you know the ceiling on exposure. Built-in gains tax applies only to the lesser of recognized gain or total net built-in gain, so documenting the starting number protects you later. Timing matters too: deferring collections or asset sales past the recognition period eliminates the tax entirely. Current year losses can also offset recognized built-in gain in some cases.