A per diem attorney travels to court and handles specific legal matters on a per diem basis.  The rates charged by per diem attorneys is usually determined by various factors including the type of matter, where the per diem has to appear and the court involved, among other things. 

Per diem attorney rates can be inexpensive when compared to the time and expense it would take for the attorney of record to prepare for the appearance, travel time to and from court, and lawyer time spent in court (which can be at least 3-5 hours of attorney time).  

Most freelance per diem attorneys can only handle matters in one courthouse or courtroom.  A per diem attorney does not usually travel to different courtrooms or courthouse.  The downside to hiring a freelance per diem attorney is that he or she will usually turn down any request that is not in the same courthouse or courtroom that he is handling on a particular day.  Another downside is that a freelance per diem attorney i usually in court until the afternoons and are difficult to communicate with and may take several days or over one week to provide an outcome or a report.  

When a freelance per diem attorney goes on vacation or is sick, then he or she will generally be unable to handle any matters and the attorney who requested coverage will be left without coverage at unexpected times.