This is a basic decision to be made early on, because a company’s formation documents, especially with respect to issuing stock, are much less complicated for a subsidiary. If you intend to manage the equity split among the owners of your business at the parent company level, then setting up a subsidiary is the best path. If you do not want the equity split of the new U.S. company to mirror the split of the foreign entity (or want it to be owned in part by someone or an entity other than the foreign parent), then set up a new U.S. entity.