This CPB has been revised to state that treprostinil inhalation (Tyvaso) is considered medically necessary for the treatment of pulmonary hypertension (PH) associated with interstitial lung disease per FDA label update. This CPB has been updated to include ambrisentan tablets (Letairis) as one of the pulmonary hypertension agents for infants less than one year of age. This CPB has been updated: (i) for Dosage and Administration information, and (ii) to add and reorganize subheaders.