Let's say that you fall off a stepladder at home and hit your head.  You go to the emergency room at your local hospital. The emergency room doctor examines you, but does not send you for x-rays or a CT scan. She or he sends you home with a prescription. Or, to change this example a little bit, let's say that the emergency room doctor does send you for x-rays or a CT scan, and the radiologist at the hospital misreads the films as being normal. The next morning you are in a coma, and end up with brain damage, because no one realized that you had a fractured skull.

Sometime later, after you have sufficiently recovered and retained an attorney, you commence a lawsuit against the hospital. After it is too late for you to sue anyone else, the hospital discloses that that emergency room doctor (or radiologist) really didn't work for the hospital. He/she was a member of a group of physicians who contracted with the hospital to provide emergency room (or radiology) services to the hospital. You say "they were working in your hospital, nobody told me they were not hospital employees, how could I possibly have known that they were not hospital employees?"

The fact of the matter is that most radiologists and emergency room doctors who work in hospitals are not hospital employees. Almost all of them are members of physicians' groups who contract with the hospital to provide emergency room or radiology services to that hospital, as well as others. Some of these groups provide emergency room or radiology services to several hospitals at any given time.

You'll be happy to know that you do not have to interrogate the emergency room doctor who examines you, or the radiologist who interprets your films, as to exactly who he/she is working for. Under New York Law, if a Hospital holds a physician out to the public as being its employee, the hospital is liable for any negligence committed by that physician. This is referred to as "apparent agency". Even if the doctor is not the hospital's actual agent or employee, if the hospital allows that physician to appear to be their agent or employee, and does not tell the patients that he/she is not their agent or employee, the hospital is responsible for him/her as if he/she was their actual agent or employee.

As I'm sure you would expect, this legal principle does not apply in a situation where your family doctor, or a surgeon selected by you, treats you in a hospital. It only applies to those physicians who appear to be employees of the hospital, and whom you would have no way to knowing are not employees of the hospital.