Let's say you were to fall off the ladder while putting up your trademark, Clark Griswold-style Christmas lights. You're rushed to the emergency room, evaluated, and stabilized. Then the hospital has several options: They can send you home or admit you as an inpatient for further treatment. But increasingly, hospitals are shuffling older patients to a third alternative, a category called "observation status" under which patients are monitored (and often treated) by doctors, but never formally "admitted" in the eyes of either the hospital or the insurer. As it turns out, this classification is great for hospitals, but it can be far more expensive for patients.