Dual Citizenship Country Guide
The US allows dual citizenship, but your home country may not. Naturalizing as a US citizen could automatically revoke your original citizenship in some countries. Look up your home country's policy before filing N-400.
US Policy on Dual Citizenship
The United States generally permits dual citizenship. There is no law requiring US citizens to renounce other nationalities, and the State Department acknowledges dual citizenship exists. However: (1) US immigration law requires you to renounce "allegiance to foreign states" during naturalization — this is a formal declaration, not legally binding on you; (2) The State Department may not recognize your foreign citizenship in some situations; (3) Some federal jobs (security clearance roles) may be affected by dual citizenship. Consult an attorney if you are entering security-cleared work.