Xfinity Internet customers in the following locations have the Terabyte Data Internet Usage Plan:
The Terabyte Internet Data Usage Plan is suspended in Maine, effective December 1, 2016.
The Terabyte Internet Data Usage Plan does not currently apply to Xfinity Internet customers on our Gigabit Pro tier of service. The plan also does not apply to Business Internet customers, customers on Bulk Internet agreements, and customers with Prepaid Internet.
For additional information about Comcast's Data Usage Plan see here: https://dataplan.xfinity.com/faq/
For frequently asked questions about Comcast's Data Usage plan see here: https://www.xfinity.com/support/articles/data-usage-plan?
and here: https://dataplan.xfinity.com/faq/