Prostacyclin compounds and compositions comprising the same are provided herein. Specifically, prostacyclin compounds comprising treprostinil covalently linked to a linear C2-C18 alkyl, branched C3-C18 alkyl, linear C2-C18 alkenyl, branched C3-C18 alkenyl, aryl, aryl-C1-C18 alkyl or an amino acid or a peptide (e.g., dipeptide, tripeptide, tetrapeptide) are described, for example, for administration via subcutaneous or intravenous infusion to a patient in need of pulmonary hypertension treatment. The linkage, in one embodiment, is via a carbamate, amide or ester bond. Prostacyclin compounds provided herein can also include at least one hydrogen atom substituted with at least one deuterium atom.