Your son has a full-time job, earns $60,000 a year, and pays his own rent, but his phone is still sitting comfortably on the family plan you’ve paid since high school. Maybe it’s only $50 or $75 a month, so you’ve never considered paying adult children’s bills a serious financial problem. Yet cellphone bills are among the most common expenses parents continue covering for young adults, according to research on the increasingly blurry transition to financial independence. The question isn’t whether helping your child is inherently wrong, because plenty of parents can comfortably afford it and genuinely enjoy providing some support. The better question is whether the arrangement still serves a purpose or simply continues because nobody has ever decided when it should end.