As organ donation rates remain unable to meet the needs of individuals waiting for transplants, it is necessary to identify reasons for this shortage and develop solutions to address it. The introduction of kidney paired donation (KPD) programs represents one such innovation that has become a valuable tool in donation systems around the world. Although KPD has been successful in increasing kidney donation and transplantation, there are lingering questions about its legality. Donation through KPD is done in exchange for-and with the expectation of-a reciprocal kidney donation and transplantation. It is this reciprocity that has caused concern about whether KPD complies with existing law. Organ donation systems around the world are almost universally structured to legally prohibit the commercial exchange of organs. Australia, Canada, and the United States have accomplished this goal by prohibiting the exchange of an organ for "valuable consideration," which is a legal term that has not historically been limited to monetary exchange. Whether or not KPD programs violate this legislative prohibition will depend on the specific legislative provision being considered, and the legal system and case law of the particular jurisdiction in question. This article compares the experiences of Australia, Canada, and the United States in determining the legality of KPD and highlights the need for legal clarity and flexibility as donation and transplantation systems continue to evolve.