If you’ve dealt with getting a prescription filled at a pharmacy you may have come across this term at some point. When something requires prior authorization it means the insurance company must approve coverage for it before it can be purchased. Many children with feeding tubes run into this for acid reflux medications but there are other types of medications which also have these sorts of restrictions.
The mechanics for prior authorization can be extremely confusing because policies between insurance companies differ significantly. One company may approve a brand without any objection while it might be nearly impossible to get approval for anything else. If you switched insurance companies you might well find that one brand which was preferred before is almost impossible to get approval for once companies change.