Empire Blue (Anthem): https://www.empireblue.com/machine-readable-file/search/
United Healthcare: https://transparency-in-coverage.uhc.com/
Aetna (Seems like the right page, but I don't see any download links — possibly because they haven't been posted yet): https://health1.aetna.com/app/public/#/one/insurerCode=AETNA...
Search keywords: https://www.google.com/search?q=machine+readable+files+trans...