You cannot, upon getting a prognosis of six months or less to live, just move into an inpatient unit and hang out there until you die. Medicare and other insurance providers have guidelines about what constitutes an appropriate inpatient admission. Symptom management, such as uncontrolled pain, is an example of an acceptable inpatient admission.
The vast majority of hospice patients are in their homes. They, and their caregivers, receive the support of nurses, doctors, nursing assistants, social workers and pastoral counselors. It's a beautiful concept. Not perfect...but beautiful.