Requirements to work as a freelance or official court reporter vary from state to state, and from court to court. Most states require either a state certification, a national certification, or a combination of both.
Examples of state certifications would be the Illinois CSR (Certified Shorthand Reporter) or the Alabama CCR (Certified Court Reporter). The certification exams usually have two components to them: written knowledge tests (WKT) and skill examinations. The WKT may contain questions on legal terminology, medical terminology, grammar and punctuation, court procedures, and state laws that govern the actions of court reporters.
Courts may administer their own tests or accept a state or national certification for applicants.
The National Court Reporters Association (NCRA) administers the national tests. The entry-level court reporter certification is called the Registered Professional Reporter (RPR). It consists of a written knowledge test and three skill tests. Skill tests consist of five minutes of dictation that you write on your shorthand machine. You then have 75 minutes to transcribe your notes into a transcript that will be graded. Accuracy requirements are a minimum of 95% transcribed accuracy.
Test 1: Literary material at 180 words per minute.
Test 2: Jury charge material at 200 words per minute.
Test 3: Two-voice testimony at 225 words per minute.
Captioners also have a national certification. Not all captioning companies require it, but it is a prestigious certification to hold.
You can learn more about certifications at the following sites:
National Court Reporters Association certification page
Simply Steno Compilation of Court Reporting State Requirements