Our own eeka reports  that while the state health-insurance system properly accounts for her spouse as her spouse, it's decided said spouse is the "stepmother" of their kid:
They also have me listed as our child's "mother" and spousal unit as child's "stepmother." "Stepparent," while often someone who provides amazing parenting to a child, is not someone who is fully a legal parent to said child.
We jointly adopted said child in Massachusetts, as a married couple. On our health insurance application, we listed ourselves as spouses and our child as our child.
Apparently the people who manage the healthcare benefits decided that the family relationships we have that are backed up by a bunch of legal paperwork aren't actually real.
- Parenting