Check your state laws about this. Many states have a law that requires insurance companies to pay for any licensed caregiver who is licensed by the state to provide that service, so a licensed midwife would *have* to be covered if an OB was covered. It doesn't matter where the service is provided, at home or at a birth center or at a hospital, because the insurance doesn't provide the "where" only the "who." Your state might also have a provision that requires out-of-network coverage to be covered at the in-network rate if an in-network provider isn't available within a certain number of miles, for birth that's generally 50 miles from your home. Call your local state reps and ask them to check into what your state's law says, and if it's not what you want, tell them to start the process to change it! And finally, most states have a medical review board that can review your case & order your insurer to pay, if you make a good case about why they should, so don't let this drop. You've got a great start, keep it up!
The number of U.S. states in which a person can marry the person they love regardless of gender: 30 and counting!