Imagine a U.S. company wants to pay lower taxes by simply changing its legal home to another country. It keeps its headquarters and operations right where they are. That is a corporate inversion, and the tax law has built high walls to stop it. In this chapter, we’ll see the powerful rules that prevent these paper‑only moves from wiping out U.S. tax, and we’ll learn how even honest cross‑border reorganizations can trigger special charges that trap deferred income.