| CBWI | Chesapeake Bay Watershed Initiative | unable to verify |
| CORAL | COral Reef Airborne Laboratory | site not responding |
| ETIB | Experimental Transplantation and Immunology Branch | unable to verify |
| FedRelay | Federal Relay Service | expired |
| FPI | Federal Preservation Institute | unable to verify |
| IPD | International Programs Division | unable to verify |
| ITC | NRCS Information Technology Center | unable to verify |
| MLRS | Mineral & Land Records System | down for maintenance |
| MPP | Migrant Protection Protocols | site archived |
| MSP | Mathematics and Science Partnerships | site archived |
| NBSDB | National Building Stone Database | unable to verify |
| OSHC | Office of Sustainable Communities | unable to verify |
| RHESSI | Reuven Ramaty High Energy Solar Spectroscopic Imager | decommissioned |
