It depends on what you do. Pediatric malpractice insurance will run about fifteen thousand per year. If you're an obstetrician it will run about fifty thousand a year. Malpractice insurance is becoming very expensive. The more you touch a patient the more your insurance will cost.
Pediatricians do very little surgical procedures thus the cost is less.
I think you have to have malpractice insurance by law. This may vary from state to state. I don't know any physicians who don't carry malpractice insurance. If you don't have insurance and you get sued you can loose everything you own. It has become a legal problem, mainly because of the way the court system works.