Medical billing and coding specialists don’t usually get involved with “hard” or intense collection efforts - this is usually left to the collection agency. But they usually are involved with “soft” type collections which may be a courtesy phone call or letter reminding the patient their insurance company has paid, they have a past due balance, and offer to make payment arrangements. For the more delinquent accounts it may be a notification that their account will be turned over to collections if arrangements are not made soon.