The NTSB found that the train was travelling at a speed of 82 miles an hour in a 30 mph zone.
No problems were found with the train's signaling systems, brakes and mechanical equipment, or with the track.
The report also said Metro-North has determined that the accident cost $9 million.
The southbound train derailed in the Spuyten Duyvil section on Dec. 1 as it was headed from Poughkeepsie to Grand Central Terminal.
A lawyer and union leader for the derailed train's engineer, William Rockefeller, have said he briefly nodded or experienced a daze at the controls.
The report does not draw any conclusions about what caused the wreck.
An NTSB spokesman says new information and a conclusion are probably months away.
The MTA is implementing new safety measures at the site of the derailment.
The new system will warn engineers of the approaching speed reduction and can automatically enforce speed restrictions at four other curves.