( IN ORDER, LOWEST TO HIGHEST )
* Med Students (3rd/4th year)
Medical school lasts four years, both in allopathic (MD) and osteopathic (DO). Third and fourth year are spent in the hospital. They are at the very bottom, and have virtually no pull as far as decisions.
* Interns
Internship is the first year of residency. This lasts only one year before the rank of Resident is achieved. They must have decisions approved by an attending.
* Residents
Residency lasts between 3 and 5 years, depending on the specialty. In the resident's last year of residency, he or she is known as a Senior Resident.
* Chief Residents
Chief Residents are those who choose to stay in their residency instead of going on to become an Attending, and teach lower-ranking and less-experienced residents.
* Attendings
After residency comes the attending position, assuming that the student did not become a Fellow at another hospital. Attendings can take interns under their wings, so to speak, and approve their decisions.
* Department Chief
Highest-ranking attending. They are the head of their particular department, and have final say in all department decisions.
the others
There are, of course, other medical workers associated with the hospital. There are:
* Nurses
* Nurses' Aides
* Paramedics
* Physicians' Assistants
...But they do not fit properly into the hierarchy listed above. They are all vital parts of the hospital, though, and every bit as important as the ones listed above.