I have Blue Cross PPO. They cover everything and rarely a question asked. Perhaps it is the fact that MA has strict laws about providing mental health services? Not everyone has the same benefits I have, but even when I had my cheap teacher's insurance in AZ, they covered some payment.
It's worth it to check, though.
Or, Norse, you could investigate one of the religiously affiliated family services agencies. You don't have to be Jewish to go to Jewish Family Service, or Catholic to go to Catholic Charities. And, they have a sliding scale. They don't preach their values to their clients.