I have an HSA through my employer and contributed 3450, my wife has an HSA for herself and our kids, contributed 5500. TTax is still saying she paid excess. Why?

[AnthonyC · Accepted solution]

Its because there is an excess contribution - the family limit ($6,900) is for the total of contributions made by both taxpayers, even if both taxpayers have their own HSAs.  

Example:  This means that one taxpayer can’t contribute $6,900 to his/her HSA and the other contribute $3,450 to the other HSA – the $6,900 limit applies to the total of all HSA contributions credited to the family 

From IRS Pub 969

Rules for married people.

 If either spouse has family HDHP coverage, both spouses are treated as having family HDHP coverage. If each spouse has family coverage under a separate plan, the contribution limit for 2018 is $6,900. You must reduce the limit on contributions, before taking into account any additional contributions, by the amount contributed to both spouses’ Archer MSAs. After that reduction, the contribution limit is split equally between the spouses unless you agree on a different division.