Edwin Gallart, 41, of The Bronx, was stuck with his arm in the toilet for 90 minutes, The Advocate of Stamford reported.
Crew members were alerted to the problem at about 59th Street.
The conductor called for a supervisor, who boarded the train at 125th Street to help.
As the train continued north on the Harlem line, the trainmaster tried to remove Gallart's arm from the stainless steel commode, a railroad spokesman told the paper.
Twenty minutes later, police and firefighters boarded the train at the Fordham station and began helping Gallart.
Meanwhile, passengers were evacuated and thousands of commuters were delayed because the train sat blocking the tracks as the rescue work continued.
Firefighters tried a variety of methods to extricate Gallart's arm.
They ended up taking apart the entire toilet.
Gallart's arm was removed and he was treated and released from a local hospital.
His cell phone wasn't retrieved.Post Wire Services