just adopted my grandson due to unfortunate circumstance, i'm retired on social security and on medicare and he has medicaid . will he keep his medicaid plan

Probably. I suggest you call them

Like Kimmt said. Call them but it's better to go in and bring all the paper work you have on him. Such as Adoption papers, birth certificate, Social security number if you have it available. Bring what ever u have because they will want you to bring it back to them.And your ID!! God bless!!