| 1 | MDI | MD Flugfelagid EHF (MD Airlines Ltd.) | IATA: 1I, Callsign: Delta Ice, IATA designator changed to W3 | IS | AVCODES |
| 2 | MDI | MD Flugfelagid EHF (MD Airlines Ltd.) | IATA: W3, Callsign: Delta Ice, IATA designator changed from 1I | IS | AVCODES |
| 3 | MDI | IAS Medical Ltd | Callsign: Medops, | GB | AVCODES |
| 4 | MDIB | MAST DISTRIBUTORS INC | | | SCAC4 |
| 5 | MDIC | MH DISTRIBUTION INC | | | SCAC4 |
| 6 | MDII | M D C | | | SCAC4 |
| 7 | MDIJ | MARX DISTRIBUTION INC | | | SCAC4 |
| 8 | MDIK | MDI SHELLFISH CO INC | | | SCAC4 |
| 9 | MDIM | MADIC, M INC | | | SCAC4 |
| 10 | MDIN | MEDINA CEDENO, JOSE FRANCISCO | | | SCAC4 |
| 11 | MDIO | MT DIABLO RECYCLING | | | SCAC4 |
| 12 | MDIQ | MID-ISLAND DELIVERY SYSTEMS INC | | | SCAC4 |
| 13 | MDIR | MERCHANTS DISTRIBUTION SERVICE, LTD | | | SCAC1 |
| 14 | MDIR | MERCHANTS DISTRIBUTION SERVICE LTD | | | SCAC4 |
| 15 | MDIT | MEDI-DART INC | | | SCAC4 |
| 16 | MDIU | M.D. SRL | | I | BIC |
| 17 | MDIX | Modern Dispersions, Inc. | 7/2000-7/2005 (not listed)_ | | NAKINA |
| 18 | MDIX | Modern Dispersions, Inc. | Jul-00 | | NRHS |
| 19 | MDIX | MODERN DISPERSIONS INCORPORATED | | | PWRC |
| 20 | MDIX | Modern Dispersions | | | RSRV |
| 21 | MDIX | MODERN DISPERSIONS INC | | | SCAC4 |
| 22 | MDIY | MDI YACHT TRANSPORT LLC | | | SCAC4 |
