The 30-year-old woman was standing on the platform just after noon at the 5th Avenue and 53rd Street station.
The victim was shoved and hit her head on a train as it was leaving the station before falling to the tracks.
Bystanders at the station helped pull her off the tracks and back onto the platform as the suspect got away.
The victim underwent emergency surgery and is now in critical condition with head injuries.
Authorities believe the attack was random and the victim was either on her way to or from work at the time of the assault.
The suspect, identified as Sabir Jones, is described as a 39-year-old man, 6 feet tall, last seen wearing a white grey shirt and grey sweatpants.
Authorities said the suspect is known to the department.
While officials say subway crime is down overall, that is not any consolation to the family of the young woman who is fighting for her life.
"The past year we have made tremendous progress on subway crime, crime is 9% down where it was the past year before COVID," said MTA Chair and CEO Janno Lieber. "New Yorkers put up with a lot, what they cant put up with is people randomly coming up to them, which appears to be the case here, and attacking them."
Lieber went on to call on more to be done to help people with mental issues get out of the public space and into treatment.
The NYPD says there have been 15 incidents of people being pushed onto the subway tracks so far this year compared to 22 by this time last year.
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