One can have:
- a solo anesthesiologist
- a solo CRNA (in certain medical facilities from certain "opt-out" states)
- a CRNA under the "supervision" of any MD (up to 1:8 coverage)
- a CRNA under the "medical direction" of any MD (the traditional physician extender model, up to 1:4 coverage, requires satisfying 7
TEFRA criteria for Medicare billing)
- an AA always under the medical direction of an anesthesiologist
- an anesthesiology resident or fellow under the medical direction of an anesthesiologist (up to 1:2 coverage)
Did I miss anything?