Do "PER DAY" means that each doctor should bill that code once per day or does it mean that code should appear on the patient chart once for every day. and example of this code is the subsequent hospital care codes such as 99231.
Per day means that the single code encompasses all of that particular service done on a given date. In most cases, as for 99231, it can only be billed once per day by each individual provider. However, there are a few codes, e.g. those in the pediatric critical care section, where the CPT instructions state that the code may only be used by only one single physician per date of service, and some payers may have policies limiting the number of physicians or specialties that may bill a 'per day' code per patient per day. In addition, most payers treat providers of the same practice and specialty to be a single provider, so if that was the case, you would also only bill once for the services for multiple providers on the same date.