R.A.C. (Random Audit Contractor) reviews health claims from 2007 onward and can issue demand notices to recoup overpayments. Hospitals can appeal decisions through 5 levels, with specialized help writing appeals up to level 3. Appeals focus on physician admit orders and medical necessity, using standards like Milliman Care Guidelines. M.A.C. (Medicare Administrative Contractor) processes and pays claims according to CMS guidelines, denying claims that do not meet standards. Appeals emphasize expected length of stay over 24 hours or 2 midnights per CMS guidelines, also using standards like Milliman Care Guidelines. Commercial appeals are written for non-CMS insurers and follow a format adaptable to