Can you use Medicaid in another state?

My boyfriend is moving from another state to where I live and he has Medicaid until I can put him on mine which will be awhile. He is  diabetic so of course a concern is getting in insulin. It takes about a month to get Medicaid here I’m not sure if it’s like that everywhere. Could he still use his Medicaid from other state here? I’ve heard you can and I’ve heard you can’t.