Public Health grad student here. cdahlkvist has a really good point.

DO NOT GIVE A BLANKET HIPAA PERMISSION STATEMENT TO GEICO

It is scary what they can do with it, even though I asume they aren't your health insurance company.

Talk to representatives there and see what the minimum amount of documentation you need to provide them with is.

Full access can open up a can of worms with unauthorized users that you do not want to deal with.