[...] many providers must go through billing "clearinghouses," which in turn file the bills with the managed care companies. [...] for prescription drug claims, the managed care companies contract that work out to pharmacy benefit management companies to determine which drugs to authorize. The Kentucky Medical Association has been tracking member complaints, and most concerns stem from a higher volume of prior authorizations that managed care organizations require for expensive drugs and "high end" diagnostic services, such as CAT scans and MRIs.