American Business for American Companies Act of 2021 This bill makes permanent and expands restrictions that prohibit federal agencies from awarding contracts to inverted domestic corporations. (Similar restrictions have historically been included in annual appropriations measures.) Specifically, an agency may not award a contract for the procurement of property or services (including a defense contract) to (1) any foreign incorporated entity determined to be an inverted domestic corporation or any subsidiary of such entity, or (2) any joint venture more than 10% of which is held by such an entity or subsidiary. An inverted domestic corporation is a company that was previously incorporated in the United States or was a partnership in the United States but is now incorporated in a foreign country despite (1) a majority of the company being owned by the owners of the former domestic entity, or (2) management of the company primarily occurring in the United States.