There have been users posting in the Macbook networking forums that they were using Verizon and Sprint broadband cards but I am sure AT&T would work also
This thread has been closed by the system or the community team.
You may vote for any posts you find helpful, or search the Community for additional answers.
Laptops: Sprint Wireless PC or Mac?
Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.