351 Exchange

The core mechanic

IRC §351 is a provision that generally allows shareholders to transfer property to a corporation without recognizing gain, provided that the transferors control the corporation immediately after the exchange. In the concentrated stock context, this is used to contribute appreciated employer stock to a newly formed (or existing) corporation in exchange for corporate shares. The gain embedded in the contributed stock is not recognized at contribution — it is "carried over" into the basis of the corporate shares you receive.

Once inside the corporation, the concentrated stock can be sold and reinvested into a diversified portfolio. The corporation pays corporate income tax on the sale, but this can be structured to minimize the immediate individual-level tax burden. Your corporate shares represent diversified exposure rather than a single name.

Where it diverges from a 721 exchange

A 721 exchange contributes stock to a partnership fund run by a third-party manager. A 351 exchange contributes stock to a corporation you control (or co-control). This gives you more flexibility over what the corporation does with the proceeds — but it also requires you to set up and maintain the corporate structure, manage the entity's investments, and navigate the double-taxation dynamics of a C-Corp.

Because corporate earnings are taxed at the entity level and again when distributed as dividends, 351 exchanges involve careful structuring to avoid the double-tax drag outweighing the deferral benefit. This is why legal and tax counsel is not optional — it's a requirement of any 351 exchange worth considering.

When a 351 exchange makes sense

This strategy tends to make sense when: the position is large enough that the corporate setup costs are negligible relative to the tax deferral benefit; the investor has a genuine long time horizon and does not need near-term liquidity; the investor has complex estate planning goals that can be integrated with the corporate structure; and there is tolerance for the ongoing administrative requirements of maintaining a corporate entity.

It is less commonly used than 721 exchange funds because the 721 structure is simpler and managed by established third-party funds. But for clients with very large positions or specific control preferences, a 351 structure can be the right answer.

Key risks and considerations

The IRS scrutinizes 351 exchanges closely. The exchange must satisfy several technical requirements — including the "control" test — or the gain will be recognized immediately. Anti-avoidance rules can apply if the exchange appears to be primarily motivated by tax avoidance rather than legitimate business purposes. Every transaction of this type requires a qualified tax attorney and CPA before any shares are moved.

There is also the practical reality that once assets are inside the corporation, getting them back out without triggering tax requires careful planning. This is not a reversible transaction.