| Abbreviation | Definition |
|---|---|
| FITW | Federal Income Tax Withholding |
| FIU | Federal Investigations Unit |
| FIU | Financial Intelligence Unit |
| FJC | Federal Judicial Center |
| FKM | Fuzzle Killing Movement |
| FLAW | Four-Letter Acronymic Word |
| FLEGT | Forest Law Enforcement, Governance and Trade |
| FLETC | Federal Law Enforcement Training Center |
| FLM | Food Labor And Mileage |
| FLOTUS | First Lady Of The United States |
| FLRA | Federal Labor Relations Authority |
| FLU | Influenza |
| FM | Federated States of Micronesia |
| FM | Forms Missing |
| FMA | Facility Management Agreement |
| FMC | Federal Maritime Commission |
| FMCS | Federal Mediation and Conciliation Service |
| fmd(S) | Field Management Directive(s) |
| FmHA | Farmers Home Administration |
| FML | Family Medical Leave |