A PLLC is a form of an LLC for professionals. Some states prevent physicians, dentists, lawyers, accountants and other professionals from operating as limited liability companies. There should be no misunderstanding that these types of business cannot shield an individual from malpractice or fiduciary irresponsibility.
That does not mean most states don’t allow those businesses to exist. They just fall under a slightly different category that still allows for the tax versatility of an LLC, and that is the PLLC. If you carry malpractice insurance or have a legal fiduciary responsibility to your clients, you’re likely in need of a PLLC. If you are still not sure, consult an attorney for guidance.