Express Scripts Holding Company is the largest pharmacy benefit management (PBM) organization in the United States. The company offers a variety of PBM services including retail drug card programs and Home Delivery services amongst others. Express Scripts Holding was started in 1986 as a joint venture between Medicare Glaser Inc. and Sanus Corp. Health Services. The company is headquartered in St. Louis, Missouri, United States. Express Scripts Holding currently employs 25,900 staff worldwide.