That's because Illinois passed "Charlie's Law" in July of 2017. This made it mandatory for all insurance companies in the state to provide coverage for IVIg infusion therapy for PANDAS/PANS patients. Without insurance coverage, IVIg can costs families $1000's per month.
Now, using IVIg to treat these conditions is considered "off-label". That means that it's an FDA approved treat for other illnesses. But it is not approved for this particular type of use.
And yet, it works...very well.
So what are you to do if you live in Texas or any other state? Where it is up to the insurance companies to decide if IVIg is an approved treatment or not? Clinical evidence supports it. But the FDA still has not approved it as such.
Even within a state, one company may agree to IVIg coverage while another might not.
Neither seems like a fair option. A key element of insurance reform has to be creating uniform standards for coverage of efficacious treatments.