Are children under 16 always covered at no cost?

Answer:

Yes, as long as the adult Family Member with whom they are traveling with is covered. The children can be covered even if they are staying in a different room or cabin than the covered adult Family Member. There is, however, an additional charge for children if you purchase the Optional Medical Upgrade and/or the Optional Flight Coverage.
* Travel Plus and TraveLite only.
"Family Member" means your: legal spouse or common-law spouse (where legal), legal guardian, legal ward, son or daughter (adopted,foster, step or in-law), brother or sister (includes step or in-law), parent (includes step or in-law), grandparent (includes in-law), great-grandparent, grandchild, great-grandchild, aunt, uncle, niece,nephew or Key Person, provided the Family Member resides in the United States, Canada or Mexico.