Bladder cancer is the fourth most common cancer in the United States. Urothelial carcinoma that originates from the urinary bladder is the most common subtype. These NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) provide recommendations on the diagnosis and management of non-muscle-invasive and muscle-invasive urothelial carcinoma of the bladder. This version of the guidelines provides extensive reorganization and updates on the principles of chemotherapy management.