Dr. Horning has practiced hospital emergency medicine since 1996. He attended Northwestern University Feinberg School of Medicine from 1989 to 1993, and completed a residency in Emergency Medicine at Columbia University Affiliate - Morristown Memorial Hospital in New Jersey in 1996. During his final year he was honored to serve as Chief Resident of Emergency Medicine.

He served as Emergency Medical Services Director for the Southern Region of New Hampshire, and also served as Treasurer for the New Hampshire State Chapter of the American College of Emergency Physicians, He is an active member of the American Academy of Home Care Physicians. He is a Fellow and Founding Member of the American Academy of Emergency Medicine and has been a Diplomate of the American Board of Emergency Medicine since 1997.

Dr. Horning practiced emergency medicine in Manchester, New Hampshire from 1996 to 2000, then at St. Joseph Hospital in Bellingham, Washington from 2000 to 2007.  More recently he practiced emergency medicine at Tahoe Forest Hospital in Truckee, California, and also at Tuolumne General Hospital in Sonora, California.

He relinquished his regular position in the emergency room at St. Joseph Hospital in Bellingham, Washington in 2005 to relocate with his wife and two daughters to Prague, Czech Republic for a sabbatical year. During that year he commuted to Vail and Aspen, Colorado where he provided urgent house call medical services to the resorts, hotels and local residences. He discovered that house call medicine provided the opportunity to connect with patients that he had rarely experienced in the emergency department because of time constraints. He noted that patients were appreciative of the convenient and professional service that was offered by he and his colleagues providing urgent house calls. From this experience he determined to establish a hotel and house call service for the San Francisco Bay Area offered by emergency physicians.

After a year in Prague he and his wife and two daughters returned to the United States to San Francisco to live close to family and enjoy all that the city has to offer. Dr. Horning officially launched Urgent Med Housecalls in February 2007.