Insurance companies certainly can have formularies. I noticed that there aren't any drugs on the excluded list that don't have alternatives listed. When we cha

Insurance companies certainly can have formularies. I noticed that there aren't any drugs on the excluded list that don't have alternatives listed. When we change insurance plans my kids have to change the brand name of insulin they get. Humolog, Admelog, etc. But the insurance company can't decide that they won't pay for fast-acting and slow-acting insulin. And if there is a medical reason a doctor will sign off on that indicates a specific brand is required, I believe that you can generally get even excluded medicines covered. Can insurance companies refuse to cover an FDA approved drug that doesn't have a reasonable substitute? OP discussed treatment for leukemia. An ACA plan should cover approved treatments for leukemia, but it might not cover, e.g. the latest CAR-T treatment if it's still in Phase 3. You would need to get into the study, in which case treatment would be free.