 A United States CTEPH Registry has been established under the guidance of a Steering Committee consisting of recognized physicians and scientists with expertise in CTEPH and related diseases. The mission of the Registry will be to promote a greater understanding of the prevalence, pathophysiology, evaluation, and treatment of patients with CTEPH through shared information, education, and collaborative investigation among PH centers of excellence throughout the U.S. The development of a national CTEPH registry will be an important element in the advancement of the understanding of CTEPH and improvement in the care of patients who suffer from this debilitating disease. 