Travel insurance plans are designed to cover the traveler from the time they leave their home, through the covered trip and back to their home. Most plans do not allow for any changes to be made to the policy once the trip has begun. Similarly, there are few plans that allow the traveler to purchase and be covered after the trip has already has begun. So, if the return date is unknown or there is a possibility that the trip may be expanded, it is a good idea to overcompensate the return date in the future. If the traveler returns home before the scheduled return date, then coverage will cease when the traveler returns to their home. Always refer to the certificate of insurance for details.