My insurance only covered one kind of nebulzer. So i assumed they would not cover the innospire go. (Not on medicare yet)

Some companies require a prescription, others don't. Unfortunately, Medicare only covers the most basic of nebulizers, and just once every 3 (or 5) years. Most supplement policies follow that too. The exception is if you are prescribed a specific inhaled antibiotic that requires a handheld, impeller type nebulizer, some policies cover 80%.
This is considered Durable Medical Equipment and comes under Medicare Part B, not Pat D Drug Coverage.
Sue