If they are exclusive providers of the smart phone you want to use, you may find that the simplest baseline isn't met. (slaw.ca)
An EPO (Exclusive Provider Organization) will not allow you to receive non-emergency services outside of the network. (majormedicalhealth.com)
Health maintenance organizations (HMOs) have strict networks and require referrals to see specialists; preferred provider organizations (PPOs) don't require referrals and let you go outside of your network, for a higher cost; and exclusive provider organizations (EPOs) have a tight network, like an HMO, but don't require referrals. (policygenius.com)