Fentanyl is on the Illinois Medicaid Preferred Drug List. Although I don't know if this includes the patch. I agree you need to call your state medicaid program and ask if they cover the fentanyl patch for non terminal pain. Perhaps they won't pay for the dose you are prescribed. But, they might pay for a lower dose.
Preferred Drug List Illinois Medicaid-
/www.illinois.gov/hfs/SiteCollectionDocuments/pdl.pdf