Metro North has released details about how commuters who couldn't use weekly or monthly tickets on the New Haven line because of the massive power outage can receive a credit. September and October monthly ticket holders will receive a 25-percent credit for each month toward the purchase of a future ticket.
If commuters turn in both tickets at once for a November monthly--that new ticket will be accepted starting October 20. Mail and Ride customers will have the credit automatically applied to their December monthly ticket.
Commuters who also have a Metro Card on their monthly ticket and still have value should request their Metro North credit at a later date. Metro North ticket windows can't transfer Metro Card value, that can only be done at subway station booths.
More information about the credits can be found on the MTA website.