The line has been hit hard by the repeated snowstorms in the New York metropolitan area.
The railroad said previously that snow and extreme cold had left about 40 percent of its New Haven line cars out of service.
Almost 70 percent of its electric fleet is over 40 years old.
The reduced schedule is in effect through March 4. It means that weekday morning and evening peak service will be reduced about 10 percent.
Metro-North says it has been working round-the-clock to repair train cars.
Schedules are available at ticket offices and on the Metro-North web site.