The first three numbers of any FBI file designation indicate the kind of offense the FBI was investigating when it opened the file. For example, a file number that begins “025” would be classification 25, or an investigation into draft evasion or violation of the Selective Service Act.
| 1 | National Academy matters |
| 2 | Neutrality Matter |
| 3 | Destruction or Overthrow of the Government |
| 4 | National Firearms Act |
| 5 | Income Tax |
| 6 | Interstate Transportation of Strikebreakers |
| 7 | Kidnapping |
| 8 | Migratory Bird Act |
| 9 | Extortion |
| 10 | Red Cross Act |
| 11 | Tax (other than income) |
| 12 | Narcotics |
| 13 | National Defense Act; Prostitution; Selling Whiskey Within Army Camps, 1920 only (obsolete) |
| 14 | Sedition |
| 15 | Theft from Interstate Shipment |
| 16 | Consolidated into Classification 69 |
| 17 | Fraud Against the Government – Veterans Administration |
| 18 | May Act |
| 19 | Censorship Matters |
| 20 | Federal Grain Standards Act, 1920 only (obsolete) |
| 21 | Food and Drugs |
| 22 | National Motor Vehicle Traffic Act, 1922-27 (obsolete) |
| 23 | Prohibition |
| 24 | Profiteering, 1920-24 (obsolete) |
| 25 | Selective Service Act |
| 26 | Interstate Transportation of Stolen Motor Vehicles and Stolen Aircraft |
| 27 | Patent Matter |
| 28 | Copyright Matters |
| 29 | Bank Fraud and Embezzlement |
| 30 | Interstate Quarantine Law (obsolete) |
| 31 | White Slave Traffic Act |
| 32 | Fingerprint Matters |
| 33 | Uniform Crime Reporting |
| 34 | Violation of Lacy Act, 1922-43 (obsolete) |
| 35 | Civil Service |
| 36 | Mail Fraud |
| 37 | False Claim Against the Government, 1922-29 (obsolete) |
| 38 | Application for Pardon to Restore Civil Rights, 1921-35 (obsolete) |
| 39 | Falsely Claiming Citizenship (obsolete) |
| 40 | Passport and Visa Matters |
| 41 | Explosives (obsolete) |
| 42 | Deserter |
| 43 | Illegal Wearing of Uniform |
| 44 | Civil Rights |
| 45 | Crime on the High Seas |
| 46 | Fraud Against the Government |
| 47 | Impersonation |
| 48 | Postal Violations (except Mail Fraud) |
| 49 | National Bankruptcy Act |
| 50 | Involuntary Servitude and Slavery |
| 51 | Jury Panel Investigation |
| 52 | Theft or Destruction of Government Property |
| 53 | Excess Profits on Wool, 1918 (obsolete) |
| 54 | Customs Laws and Smuggling |
| 55 | Counterfeiting |
| 56 | Election Laws |
| 57 | War Labor Dispute Act (obsolete) |
| 58 | Bribery; Conflict of Interest |
| 59 | World War Adjusted Compensation Act, 1924-44 (obsolete) |
| 60 | Anti-Trust |
| 61 | Treason |
| 62 | Miscellaneous-Nonsubversive |
| 64 | Foreign Miscellaneous |
| 65 | Espionage |
| 66 | Administrative Matters |
| 67 | Personnel Matters |
| 68 | Alaskan Matters (obsolete) |
| 69 | Contempt of Court |
| 70 | Crime on Government Reservation |
| 71 | Bills of Lading Act |
| 72 | Obstruction of Criminal Investigations |
| 73 | Application for Pardon |
| 74 | Perjury |
| 75 | Bondsmen and Sureties |
| 76 | Escaped Federal Prisoner |
| 77 | Applicants (Special Inquiry, Departmental, Other Gov’t Agencies) |
| 78 | Illegal use of Government Transportation Requests |
| 79 | Missing Persons |
| 80 | Laboratory Research Matters, Headquarters |
| 81 | Gold Hoarding, 1933-45 (obsolete) |
| 82 | War Risk Insurance (obsolete) |
| 83 | Claims court |
| 84 | Reconstruction Finance Corporation Act (obsolete) |
| 85 | Home Owners Loan Corporation (obsolete) |
| 86 | Fraud Against the Government – Small Business Administration |
| 87 | Interstate Transportation of Stolen Property |
| 88 | Unlawful Flight to Avoid Prosecution |
| 89 | Assaulting or Killing a Federal Officer |
| 90 | Irregularities in Federal Penal Institutions |
| 91 | Bank Robbery |
| 92 | Racketeering Enterprise Investigations |
| 93 | Ascertaining Financial Ability |
| 94 | Research Matters |
| 95 | Laboratory Examinations |
| 96 | Alien Applicants (obsolete) |
| 97 | Foreign Agents Registration Act |
| 98 | Sabotage |
| 99 | Plant Survey (obsolete) |
| 100 | Domestic Security |
| 101 | Hatch Act (obsolete) |
| 102 | Voorhis Act |
| 103 | Interstate Transportation of Stolen Cattle |
| 104 | Servicemen’s Dependents Allowance Act of 1942 (obsolete) |
| 105 | Foreign Counterintelligence |
| 106 | Alien Enemy Control |
| 107 | Denaturalization Proceedings (obsolete) |
| 108 | Foreign Travel Control (obsolete) |
| 109 | Foreign Political Matters |
| 110 | Foreign Economic Matters |
| 111 | Foreign Social Conditions |
| 112 | Foreign Funds |
| 113 | Foreign Military and Naval Matters |
| 114 | Alien Property Custodian Matter (obsolete) |
| 115 | Bond Default |
| 116 | Department of Energy, Applicant |
| 117 | Atomic Energy Act |
| 118 | Applicant, Central Intelligence Agency (obsolete) |
| 119 | Federal Regulation of Lobbying Act |
| 120 | Federal Tort Claims Act |
| 121 | Loyalty of Government Employees (obsolete) |
| 122 | Labor Management Relations Act |
| 123 | Special Inquiry, State Department, Voice of America (obsolete) |
| 124 | European Recovery Program (obsolete) |
| 125 | Railway Labor Act |
| 126 | National Security Resources Board (obsolete) |
| 127 | Sensitive Positions in the United States Government (obsolete) |
| 128 | International Development Program (obsolete) |
| 129 | Evacuation Claims (obsolete) |
| 130 | Special Inquiry, Armed Forces Security Act (obsolete) |
| 131 | Admiralty Matter |
| 132 | Special Inquiry, Office of Defense Mobilization (obsolete) |
| 133 | National Science Foundation Act Applicant (obsolete) |
| 134 | Foreign Counterintelligence Assets |
| 135 | PROSAB – Protection of Strategic Air Command Bases of the US Air Force (obsolete) |
| 136 | American Legion Contacts (obsolete) |
| 137 | Informants |
| 138 | Loyalty of Employees of International Organizations |
| 139 | Interception of Communications |
| 140 | Security of Government Employees |
| 141 | False Entries in Records of Interstate Carriers |
| 142 | Illegal Use of Railroad Pass |
| 143 | Interstate Transportation of Gambling Devices |
| 144 | Interstate Transportation of Lottery Tickets |
| 145 | Interstate Transportation of Obscene Matter |
| 146 | Interstate Transportation of Prison Made Goods |
| 147 | Fraud Against the Government-Department of Housing and Urban Development |
| 148 | Interstate Transportation of Fireworks |
| 149 | Destruction of Aircraft or Motor Vehicles |
| 150 | Harboring of Federal Fugitives, Statistics (obsolete) |
| 151 | Referral Cases from Office of Personnel Management, Applicant Loyalty |
| 152 | Switchblade Knife Act |
| 153 | Automobile Information Disclosure Unit |
| 154 | Interstate Transportation of Unsafe Refrigerators |
| 155 | National Aeronautics and Space Act of 1958 |
| 156 | Employee Retirement Income Security Act |
| 157 | Civil Unrest |
| 158 | Labor-Management Reporting and Disclosure Act of 1959 (obsolete) |
| 159 | Labor-Management Reporting and Disclosure Act of 1959 |
| 160 | Federal Train Wreck Statute |
| 161 | Special Inquiries for White House, Congressional Committees, and Other Government Agencies |
| 162 | Interstate Gambling Activities |
| 163 | Foreign Police Cooperation |
| 164 | Crime Aboard Aircraft |
| 165 | Interstate Transmission of Wagering Information |
| 166 | Interstate Transportation in Aid of Racketeering |
| 167 | Destruction of Interstate Property |
| 168 | Interstate Transportation of Wagering Paraphernalia |
| 169 | Hydraulic Brake Fluid Act (obsolete) |
| 170 | Extremist Informants (obsolete) |
| 171 | Motor Vehicle Seat Belt Act (obsolete) |
| 172 | Sports Bribery |
| 173 | Civil Rights Act of 1964 |
| 174 | Explosives and Incendiary Devices |
| 175 | Assaulting, Kidnapping or Killing the President |
| 176 | Antiriot Laws |
| 177 | Discrimination in Housing |
| 178 | Interstate Obscene or Harassing Telephone Calls |
| 179 | Extortionate Credit Transactions |
| 180 | Desecrationof the Flag |
| 181 | Consumer Credit Protection Act |
| 182 | Illegal Gambling Business |
| 183 | Racketeer Influenced and Corrupt Organizations |
| 184 | Police Killings |
| 185 | Protection of Foreign Officials and Official Guests |
| 186 | Real Estate Settlement Procedure Act of 1974 |
| 187 | Privacy Act of 1974 |
| 188 | Crime Resistance |
| 189 | Equal Credit Opportunity Act |
| 190 | Freedom of Information / Privacy Acts |
| 191 | False Identity Matter (obsolete) |
| 192 | Hobbs Act – Financial Institutions; Commercial Institutions |
| 193 | Hobbs Act – Commercial Institutions (obsolete) |
| 194 | Hobbs Act – Corruption of Public Officials |
| 195 | Hobbs Act – Labor Related |
| 196 | Fraud by Wire |
| 197 | Civil Actions or Claims Against the Government |
| 198 | Crime on Indian Reservations |
| 199 | Foreign Counterintelligence – Terrorism |
| 200 | Foreign Counterintelligence Matters |
| 201 | Foreign Counterintelligence Matters |
| 202 | Foreign Counterintelligence Matters |
| 203 | Foreign Counterintelligence Matters |
| 205 | Foreign Revenue Sharing |
| 205 | Foreign Corrupt Practices Act of 1977 |
| 206 | Fraud Against the Government |
| 207 | Fraud Against the Government |
| 208 | Fraud Against the Government |
| 209 | Fraud Against the Government |
| 210 | Fraud Against the Government |
| 211 | Ethics in Government Act of 1978 |
| 212 | Foreign Counterintelligence – Intelligence Community Support |
| 213 | Fraud Against the Government |
| 214 | Civil Rights of Institutionalized Persons Act |
| 215-229 | Foreign Counterintelligence Matters |
| 230-240 | FBI Training Matters |
| 241 | DEA Applicant Investigations |
| 242 | Automation Matters |
| 243 | Intelligence Identities Protection Act of 1982 |
| 244 | Hostage Recuse Team |
| 245 | Drug Investigative Task Force |
| 246-248 | Foreign Counterintelligence Matters |
| 249 | Toxic Waste Matters |
| 250 | Tampering with Consumer Products |
| 251 | Controlled Substances |
| 252 | National Center for the Analysis of Violent Crime/Violent Criminal Apprehension Program – NCAVC/VI-CAP |
| 253 | Fraud and Related Activity in Connection with Identification Documents |
| 254 | Destruction of Energy Facilities |
| 255 | Counterfeiting of State and Corporate Securities |
| 256 | Hostage Taking – Terrorism |
| 257 | Trademark Counterfeiting Act of 1984 |
| 258 | Credit and/or Debit Card Fraud |
| 259 | Security Clearance Investigations Program |
| 260 | Industrial Security Program |
| 261 | Security Office Matters |
| 262 | Overseas Homicide – Attempted Homicide |
| 263 | OPR – Office of Professional Responsibility Matters |
| 264 | Computer Fraud and Abuse |
| 265 | Acts of Terrorism in the United States – International Terrorists |
| 266 | Acts of Terrorism in the United States – Domestic Terrorists |
| 267 | Drug Related Homicide |
| 268 | Engineering Technical Matters – FCI |
| 269 | Engineering Technical Matters – Non-FCI |
| 270 | Cooperative Witnesses |
| 271 | Arms Control Treaty Matters |
| 272 | Money Laundering |
| 273 | Adoptive Forfeiture Matters – Drugs |
| 274 | Adoptive Forfeiture Matters – Organized Crime |
| 275 | Adoptive Forfeiture Matters – White Collar Crime |
| 276 | Adoptive Forfeiture Matters – Violent Crimes and Major Offenders |
| 277 | Adoptive Forfeiture Matters – Counterterrorism |
| 278 | President’s Intelligence Oversight Board Matters |
| 279 | Weapons of Mass Destruction |
| 280 | Equal Employment Opportunity Matters |
| 281 | Organized Crime Drug Investigations |
| 282 | Color of Law |
| 283 | Foreign Counterintelligence Investigations |
| 284 | Economic Counterintelligence |
| 285 | Acts of Economic Espionage |
| 286 | Freedom of Access to Clinic Entrances |
| 288 | Computer Intrusion – Criminal |
| 289 | Witness Security Program |
| 290 | Alien Terrorist Removal Court |
| 292 | Domestic Emergency Support Team |
| 293 | Foreign Emergency Support Team |
| 295 | Intellectual Property Rights |
| 296 | Integrity Committee Matters |
| 297 | Inspection Matters |
| 298 | National Sex Offender Registry – Violations |
| 300 | Counterterrorism Preparedness |
| 301 | Missing Persons DNA Database |
| 302 | Foreign Counterintelligence Investigations |
| 303 | Foreign Counterintelligence Investigations |
| 304 | Foreign Counterintelligence Investigations |
| 305 | Innocent Images National Initiative |
| 306 | Serial Killings |
| 307 | Foreign Counterintelligence Investigations |
| 308 | ERT Administrative Matters |
| 309 | Human Rights Offenses |
| 310 | Foreign Counterintelligence Investigations |
| 311 | Foreign Counterintelligence Investigations |
| 312 | Cyber Crime – Training Received and Provided |
| 314 | InfraGard |
| 315 | International Terrorism Investigations |
| 316 | Cyber Crime – Other |
| 318 | Corporate Fraud; Prime Bank and High-Yield Investment Fraud, Insider Trading, Market Manipulation |
| 319 | Administrative Records |
| 321 | Operations/Program Management |
| 322 | Bioterrorism Risk Assessment Matters |
| 323 | Hazardous Material Response Team |
| 324 | Foreign Counterintelligence Investigations |
| 325 | Foreign Counterintelligence Investigations |
| 326 | Foreign Counterintelligence Investigations |
| 327 | Foreign Counterintelligence Investigations |
| 329 | Mortgage Fraud |
| 330 | Advanced Technologies Investigations |
| 332 | Media Leak |
| 333 | Legal Advice and Opinions |
| 800 | Intelligence Program |
| 801 | International and Domestic Terrorism |
| 802 | Counterintelligence |
| 803 | Cyber |
| 804 | Criminal |
| 805 | Directorate of National Intelligence Requirements |
| 806 | Directorate of National Intelligence, Other |
| 807 | Weapons Of Mass Destruction |
| 808 | Foreign Intelligence Program |
| 809 | Foreign Intelligence Program |
| 810 | Foreign Intelligence Program |
| 811 | Foreign Intelligence Program |
| 812 | Foreign Intelligence Program |
| 813 | Foreign Intelligence Program |
| 814 | Foreign Intelligence Program |
| 900 | Major Case – Terrorism |