https://en.wikipedia.org/wiki/Tertiary_referral_hospital
A tertiary referral hospital (also called a tertiary hospital, tertiary referral center, tertiary care center, or tertiary center) is a hospital that provides tertiary care, which is a level of health care obtained from specialists in a large hospital after referral from the providers of primary care and secondary care. Beyond that general definition, there is no precise narrower or more ...