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 Baluchistan might not be covered if your country’s foreign office warns against travelling there.