As Opus says, there is no such thing as a Family HSA.
It is your HDHP policy that can be Family or Self-only. "Family" means the taxpayer and at least other person, even if that person is otherwise ineligible (they are on Medicare, have conflicting employer insurance, etc.).
Note that if either spouse has Family coverage, then both spouses must report Family HDHP coverage (even if their actual HDHP policy is Self-only).
However, having said all this, both spouses (and any other eligible person on the planet, in fact) can contribute to your HSA (or your spouse's). And you can use this HSA to make payments for qualified medical expenses for both spouses and any dependent (I don't know if your son is a dependent). So using just one HSA seems like a Family HSA, but it's not.
Note that if you have two HSAs, then the contribution limit for both HSAs covers all contributions to both HSAs in the aggregate, if you have Family HDHP coverage.
As Opus says, treat the son separately.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
