This CPB has been revised to state that cardiopulmonary exercise testing (CPET) is considered medically necessary for evaluation of exercise capacity in persons who are being considered for lung transplantation or lung resection surgery if predicted post-operative forced expiratory volume in 1 second (FEV1) or predicted post-operative diffusing capacity of the lung for carbon monoxide (DLCO) (or both) are less than 30 %, or when the performance of the stair-climbing test or the shuttle walk test is not satisfactory.