In 2011 it became compulsory to have travel insurance to get a visa to Iran. When looking for a policy, make sure Iran is actually covered (ie specifically mentioned). If it's not, or if you're unsure, buy the official insurance for US$16 at the airport; the insurance desk is opposite the visa desk (you should visit the insurance desk first). Some insurers, particularly in the USA, consider the region a ‘danger zone’ and either exclude it altogether or insist on exorbitant premiums. Travel in areas such as Kordistan and Sistan va Baluchestan might not be covered if your country’s foreign office warns against travelling there.