The term quaternary care is also used sometimes as an extension of tertiary care in reference to medicine of advanced levels which are highly specialized and not widely accessed. Experimental medicine and some types of uncommon diagnostic or surgical
procedures are considered quaternary care. These services are usually
only offered in a limited number of regional or national health care
centres.
This term is more prevalent in the United Kingdom, but just as
applicable in the United States. It can be thought as a hospital where
virtually any procedure is available where as there may not be
sub-specialist with that training at a given tertiary care hosptial.
