What does PA mean after MD for a doctor?

Answer 1

MD = Medical Doctor
PA = It's a legal term to describe a separate legal entity - Professional Association. It's a form of incorporating a group of professionals, such as physicians, or dentists, or attorneys, or accountants to allow the individuals protection from lawsuits. If you wanted to sue one of the members for malpractice, you'd have to sue the professional association rather than the individual.