Founded in 1891 in New York City as the American affiliate of the historic Merck enterprise and later established as an independent U.S. company, Merck & Co., Inc. is a leading global healthcare company known as MSD outside the United States and Canada. Headquartered in Rahway, New Jersey, the company is focused on innovative medicines, vaccines, and animal health, with a long scientific legacy that includes major contributions to infectious disease treatment, vaccines, and modern biopharmaceutical research. As of December 31, 2025, Merck employed approximately 75,000 people worldwide and reported revenue of USD 65.0 billion for 2025, reflecting the scale of a business that continues to combine research intensity with a broad international commercial presence.
Updated 2026-03-19