New York City officials filed disciplinary charges against 826 educators for misconduct or incompetence over the past two years—and in at least 171 cases, teachers had to pay fines to keep their jobs.

As tenure protections for teachers come under scrutiny nationwide, a look at recent disciplinary cases shows that termination attempts often ended with fines because an arbitrator found the city didn't prove its complaints, administrators didn't give tenured teachers enough help to improve or the teachers deserved another chance....