Depending on their citizenship, your spouse and any children under the age of 21 may be eligible to join you under TD (TN-Dependent) status. If your spouse and children are Canadian citizens, they will not need a visa before they enter the United States. When they arrive at a port of entry, they will simply need to prove their Canadian citizenship, their relationship to you, and that you have been allowed to enter the United States under the TN category. They can bring documents such as their passport, a marriage or birth certificate, and a photocopy of your admission documents to demonstrate this. Non-Canadian spouses and children must apply for a TD nonimmigrant visa at a U.S. embassy or consulate before entering the United States. In cases where non-Canadian dependents would like to travel together with the Canadian to the United States, the Canadian using TN status would first need to apply for a TN visa at a U.S. embassy or consulate to enable their dependents to apply for TD visas.