1. Should I sign up for such HPDP family plan, so that my wife can get her own HSA where her contributions are tax deductible?
Yes, if you have a family plan she can have her own HSA. I assume that she is not on Medicare and is otherwise eligible.
2. Would I take care of my health expenses via my typical annual premium and savings, but cannot use any money from the HSA.
While you can’t make any contributions since you are on Medicare, you can use your existing HSA if you have one or you can use withdrawals from hers to pay your medical expenses and even your Medicare premiums.
3. Would my wife's HSA annual contributions be limited to a single, or a family maximum?
Since you can’t contribute to an HSA she can contribute to her HSA the maximum of the family plan allowed by law.
4. Would my daughter be allowed to use such HSA savings for health/ medical expenses?
As a dependent, HSA funds from your (if you have one) or your wife’s HSA can be used for your daughter’s medical expenses.
