United Network for Organ Sharing (UNOS) is the non-profit, charitable organization that serves as the nation's transplant system (Organ Procurement and Transplantation Network) under contract with the federal government. The OPTN helps create and define organ allocation and distribution policies that make the best use of donated organs. This process involves continuously evaluating new advances and discoveries so policies can be adapted to best serve patients waiting for transplants. All transplant programs and organ procurement organizations throughout the country are OPTN members and are obligated to follow the policies the OPTN creates for allocating organs.