Dr. Donald Gratton G Downs specializes in family practice in Simi Valley area. Dr. Donald Gratton G Downs, MD has a medical practice at 2655 1st Street, Simi Valley CA, and has over 31 years of experience in the field of medicine. He graduated from University Of California, San Diego School Of Medicine with his medical degree in 1986. He is affiliated with numerous hospitals, including Simi Valley Hospital & Health Care Services (CA) and more. Dr. Downs is accepting new patients at his medical office and practice location in Simi Valley, California. He is available for appointments, preventative care, medical care as well as ongoing patient care.