Psoriasis is a chronic inflammatory skin disorder that, although non-life-threatening, can have a major impact on patients’ quality of life depending on its severity and location on the body. The disease is generally characterized as mild or moderate to severe. Although many patients, particularly those with mild disease, either forgo treatment or are treated solely with a topical therapy, those with moderate to severe disease generally require systemic therapies, which include phototherapy and conventional and biological therapies, to control their disease. Topical therapies remain the mainstay of psoriasis treatment; however, heightened awareness of psoriasis as a systemic disorder has led to greater use of both conventional and biological systemic agents. In the moderate to severe psoriasis segment, the suboptimal side-effect profiles of the commonly used conventional systemics (i.e., methotrexate and cyclosporine) have opened the playing field to biologics. Four biologics are approved for psoriasis: the tumor necrosis factor-alpha (TNF-α) inhibitors Enbrel (Amgen/Stiefel/Pfizer’s etanercept), Humira (AbbVie’s adalimumab), and Remicade (Janssen’s infliximab) and the interleukin-12/23 inhibitor Stelara (Janssen’s ustekinumab). When choosing among these drugs, dermatologists increasingly prescribe Humira rather than Enbrel as a first-line TNF-α inhibitor and reserve Remicade for the most severe psoriasis. As the most recently approved biologic, Stelara, with its novel mechanism of action, is typically reserved for psoriasis patients whose disease is refractory to TNF-α inhibitors; however, owing to its favorable clinical profile and superior convenience, it has experienced strong uptake in psoriasis since its launch. Using patient-level claims data, this report tracks the share of currently marketed psoriasis drugs by line of therapy, evaluates therapy flow, and analyzes why key therapies are chosen over others.