Ring up the provider. Ask for the full coverage book, the one with all the fine print about what's covered, what isn't, and how much you'll have to pay out of pocket, and how much they're supposed to pay.
Get everything in writing, signed, sealed, delivered, with three witnesses while the signer holds her/his hand on holy tomes from three different religions. Because insurance companies are run by sick, twisted, little daemons who will gladly screw you out of decent health care.
If you don't have enough time to read the book, or if you're too ADD [like I am], there are LGBT law groups that will check over the book for you, pro bono. Some of them may even already have copies of the book and can tell you straight away if said insurance company, and plan, will cover anything from flu vaccines to GRS.