Dropping daughter's coverage

Q. I am enrolled in the Federal BCBS (self + family plan) and wanted to drop our 18-year-old daughter from the plan as she has moved out and does not associate with the family any longer. My local rep said this wasn’t possible but couldn’t state exactly why I couldn’t drop her … just said it couldn’t be done. I wasn’t comfortable with this answer and lack of explanation. If I am unable to drop her, who is responsible for the costs associated with her lifestyle?
A. Your local rep is right. There are only two enrollment categories in the FEHB program, self and self and family. The later automatically includes your spouse and any children under age 26. There is no provision in law or regulation that would allow you to pick and choose who will be included.