Since we offer our Nanodegree programs as subscriptions, we do not offer extensions at this time. If you do not graduate before your next billing date restarts, then you will just get charged for another month. If you enroll in the regular month-to-month subscription, your billing date restarts monthly from the day you enrolled.
If you enroll in the bundled subscription, your billing date restarts at the end of the bundle period. So if you don't graduate by that time, you will get auto-charged every month until you pass all the projects required for graduation.