This is a prospective, open-label, proof-of-concept study of tofacitinib, a Janus kinase inhibitor, as a steroid-sparing therapy in corticosteroid-dependent pulmonary sarcoidosis. Five patients with corticosteroid-dependent pulmonary sarcoidosis were treated with tofacitinib 5 mg twice daily. The primary endpoint was a ≥ 50% reduction in corticosteroids at week 16 with no worsening in pulmonary function or respiratory symptoms. 60% of patients (3/5) met the primary endpoint. One patient was lost to follow up prior to steroid taper, and another was withdrawn due to worsening of known neurosarcoidosis. The three patients who met the primary endpoint each tapered to ≤ 5 mg/day prednisone, respiratory symptoms improved, and spirometry remained stable. In this proof-of-concept study, the addition of a JAK-inhibitor allowed 60% of patients with pulmonary sarcoidosis to successfully taper corticosteroids. JAK-inhibitors are a promising therapy for pulmonary sarcoidosis, which require further investigation in randomized trials.Trial Registration clinicaltrials.gov NCT03793439; registered Jan 4, 2019.