How do I find out if t's in my state are required by law to carry malpractice insurance?

The T (psychiatrist) who exploited me in California did not have malpractice insurance. I learned he was not required to.

We have to keep insurance on our property or to drive- in the event we accidentally hurt someone. T's see patient after patient and have many opportunities to hurt people, by accident or on purpose....but are not required by law to carry malpractice insurance. It's not right.