The dosage schedule varies depending on the condition being treated. For plaque psoriasis and psoriatic arthritis, the recommended dose is 150 mg administered subcutaneously at weeks 0 and 4, followed by maintenance doses every 12 weeks. For Crohn’s disease, an initial intravenous infusion of 600 mg is given at weeks 0, 4, and 8, followed by a maintenance dose of either 180 mg or 360 mg subcutaneously every 8 weeks.