[IN] An insurance mystery? Medicaid and Ineligible 3rd party insurance question

Hello r/healthinsurance friends, I’m wondering if anyone has any input on this situation.

I aged out of my parents insurance (we’ll call it Plan A) when I turned 26 over a year ago. After a few months of being on a marketplace plan, I qualified for Medicaid under the Healthy Indiana Plan. I was never on both together. HIP pays for all my claims.

However, to this day, my parents will occasionally receive an EOB in the mail, addressed to my father, from Plan A. The EOB states the amount that was billed, and then that “this member is not eligible.” They are for appointments I have had in the past year, with providers I got after I got on Medicaid. It will say I owe a certain amount of money, although Medicaid has already paid. I know my providers are not billing Plan A, because besides one of them that I had for a long time, they would have never even know I was on Plan A. I called Plan A today to ask how they were getting claims/info on my appointments, and they say the only way this is possible is if the provider is billing them the claims. I also asked if they could delete me from their system (as they say I am still listed under my dad—just as not eligible), to which they said no.

I said okay, called back my providers, and they said no, they are not billing Plan A, and have no record of billing Plan A for those dates of service. Even for the one doctor who did have Plan A in their records from before, they deleted that from their records quite a while back.

At this point, I called my current Medicaid provider, to see if maybe they have info on if Smarthealth is being listed as a primary. They said I should try calling the State, which I did, and the guy at the Dept of Social/Family Services says they do not see SmartHealth as a third party. They do see CVSCaremark for my pharmacy, which was a bit strange, but could make sense if that’s what my Medicaid is using for pharmacy benefits. The EOBs in question are for medical claims though.

What is going on here? I don’t want paper EOBs with info on all my appointments and providers going to my parents house. I am not on their plan. I don’t want anything going to Plan A, but nobody is billing them that I know of. The state Medicaid office said I could get Plan A to fax them something saying that I am not eligible, but I’m not sure how that would help.

Any thought or insights would help.