In health care, dumping is the practice of taking a very ill uninsured patient out of a private hospital on some pretense and moving that patient to a public hospital in order to avoid paying for the cost of said patient's treatment.
When a person suffers a serious injury or illness and an ambulance is summoned, the paramedics will treat and transport to the nearest hospital capable fo dealing with the condition. Under American law, no hospital may refuse to treat a patient simply because they are uninsured. As of this writing, we don't just let people die. If a patient shows up at an emergency room suffering from a heart attack, they'll be treated. Naturally, such care is very expensive and as American hospitals are expected to turn a profit, treating such cases interferes with the profit motive. During the 1980s it became common for a private hospital to take such a patient, treat them to the least extent possible, put them in another ambulance and then dump them outside a public hospital, which would then be forced to bear the entirety of the patient's treatment, including any surgery, cardiac catheterization, and other expensive procedures. In the late 1980s after a report on 60 Minutes the law was changed so that no hospital could engage in such flagrant dumping. As emergencies are dispersed geographically, so to the cost of emergency care would also be dispersed between facilities.
Nevertheless dumping continues. Patients can be transferred to another hospital if said patient requires specific care available only at the larger hospital. Say in-house dialysis (very common among drug users) or neurological care. If a patient needs dialysis regularly then the transfer can be sent, even though the receiving hospital will have to bear the lion's share of the costs. The general standard is that the patient needs to be stable before transfer- temperature and blood pressure under control, bleeding controlled and pain and other initial medications provided. There also has to be a real medical need for the move, and clear communication with the admitting physician. This reduces the amount of dumping, but it still occurs.
Who pays for these people
Hospitals anticipate that they will receive a certain number of uninsured patients, and try to recover these costs by boosting their overall cost structure. They compete for profitable work to offset these losses, one reason why maternity rooms that were shared in the 1990s are now almost all private suites with HDTVs. The result tends to be higher overall healthy care costs. Private hospitals have it somewhat easier. They tend to be located in more prosperous parts of town, where insurance coverage is higher. Remember that ambulance deliveries are geographic in nature, so uninsured patients tend to go to hospitals located in the less prosperous parts of town, meaning public hospitals. The additional cost burden that comes with serving poor and indigent populations tends to fall predominantly on public hospitals, and hospitals located in poorer areas have been known to close for economic reasons, even though there is a clear need for health care in the community. Where I live in Columbus, Ohio, South Hospital closed for that very reason. Hospitals operating in poorer parts of town tend to be smaller, and are branches of larger facilities located in more prosperous (and profitable) areas.