Filing Form N-400 is the final milestone in becoming a United States citizen. However, naturalization is not an automatic right, it is a discretionary benefit granted by U.S. Citizenship and Immigration Services (USCIS). Every year, thousands of green card holders face N-400 denials due to preventable mistakes, legal disqualifications, or evidentiary gaps. Understanding why USCIS denies citizenship applications is the best way to safeguard your legal status, avoid forfeitin