Nebulizer, no. Compressor, yes. All the home health companies I have ever dealt with, even when I was making the purchase out of pocket, in person or on-line, required a prescription for the compressor, which I got from the CF clinic. I would decide which company I was going to deal with then ask the clinic to fax the script to them directly. I've never had a problem. The reason needed for the compressor is because it is a piece of medical equipment.
You can also request a script for new nebulizers every 6 mo. and specifying the quantity (one for each medication) if you are going through the insurance for your purchase. We stopped doing that though because our CF clinic hands them out, the Pari LC.