U.S. citizens do not need a visa for tourist or business travel to Romania for stay in Romania up to 90 days. A valid US passport is required. Any All non US citizens and U.S. citizen who wishes to travel to Romania for any purpose other than tourism or business negotiations (e.g. work, study, adoption, immigration, or stays longer than stipulated in the entry requirements) should contact directly, the embassy or nearest consulate.
You may visit the consulate at: http://washington.mae.ro