As far as I know, Cayston isn't covered on Medicare part B or D, perhaps because it has just been approved. TOBI definitely is, so I wonder if next year, Cayston will be on their formulary for coverage. Here is some info regarding obtaining assistance in getting Cayston if you qualify though.
Cayston® Access Program
The Cayston® Access Program assists people with cystic fibrosis and members of their care team with insurance verification, referral to participating specialty pharmacies, claims support and co-pay assistance. As part of this program, Gilead also provides assistance to qualified patients in the United States who cannot afford to pay for Cayston.
For information about the Cayston® Access Program, call 1-877-7CAYSTON (877-722-9786) Monday through Friday between 8:00 a.m. and 8:00 p.m. (Eastern).
This program was developed in conjunction with the Cystic Fibrosis Foundation Pharmacy, LLC, a wholly owned subsidiary of the Cystic Fibrosis Foundation.
Good luck, Jenn