Effective July 18, 2001, US passport holders traveling to Mongolia for official, private business and tourism for up to 90 days are exempted from visa requirements in accordance with the New Visa Policy.
US citizens must have valid passports to visit Mongolia. A visa is not required if you are visiting for no more than 90 days. Those planning to stay in Mongolia for more than 30 days must register with the Office of Immigration, Naturalization, and Foreign Citizens in Ulaanbaatar within seven days of arriving in Mongolia. If you fail to register, even for reasons beyond your control, you will be stopped at departure, not allowed to exit, and have to pay a fine.
US passport holders who have been in Mongolia for more than 90 days must obtain an exit visa to leave the country. The exit visa is obtained from the Office of Immigration and usually takes 10 days to process. Visitors to Mongolia for less than 90 days do not need any kind of exit permit or visa. Nevertheless, be aware that requests to exit Mongolia can be denied for reasons such as civil disputes, pending criminal investigation, or immigration violations. In such instances, you will not be allowed to leave the country until the dispute is resolved or a court has made a decision. The Mongolian government has the right to keep foreign citizens in custody for various time periods, without appeal, until a decision is made. There have been reports of US citizens who have been denied exit for more than two years.
Information gathered here are subject to change without prior notice. US passport holders traveling to Mongolia are advised to contact the Embassy of Mongolia for further consular assistance and confirmation.
Embassy of Mongolia