Do you need to buy your own malpractice insurance in order to work for an agency?

Hi there, wonder if anyone could tell me if it is a standard request to have your own malpractice insurance, if you want to work for an agency? And any recommendation about nurse agency will be appreciated. Thank you.
Its always a good idea to have your own malpractice insurance no matter the setting.
Thank you very much. Any idea which company is the best to buy insurance from?