The profession of “public accounting” has been regulated by states through the process of issuing CPA licenses. There is one CPA exam taken by candidates across the country, and then each state uses the pass/fail results in their process of certifying accountants. In addition to passing the exam, states generally have education, ethics, and training requirements.
The field of forensic accounting has developed rapidly over the last decade or so, with lots of new professionals practicing forensic accounting. A CPA license is generally not required when providing forensic accounting or fraud investigation services, although many professionals do maintain the CPA credential because it adds a level of credibility to their work.