The following is not legal advice. Please contact a qualified immigration lawyer for assistance with your particular case.
The law requires the USCIS to adjudicate Naturalization applications within 120 days of examination. Many applicants whose cases are taking substantially longer than that are suing the Federal Government.
According to the Tennesean.com: “Lawsuits filed against the U.S. government by immigrants trying to live in the country permanently quadrupled in three years, the plaintiffs frustrated by years-long background checks and threat of deportation.”