FASFS
FASFS in a file
FASFS on a door label
FASFS was a title awarded to doctors in the 24th century Federation. This title was listed after MD. Doctor Rich Thorne of the Taylor Hospital on Melina II had earned this title. (TNG-R: "Violations") Beverly Crusher, chief medical officer aboard the USS Enterprise-D, also held the title. (TNG: "The Loss", "Genesis")
Dr. Katherine Pulaski had earned this title, as well. This title was mentioned on the signage to her office on the USS Enterprise-D. (Star Trek: The Next Generation - The Continuing Mission, p. 77)
According to Michael Okuda, the abbreviation stands for "Fellow of the Academy of Starfleet Surgeons". [1]