| Rank | Abbreviation | Meaning |
|---|
| ***** | MCGS | Micrograms
| |
| **** | MCGS | Monitor and Control Generated System
| |
| ** | MCGS | L-2-[2-carboxy-3-(methoxymethyl)cyclopropyl)glycines
| |
| ** | MCGS | Microwave Command Guidance System
| |
| ** | MCGS | Mill Creek Generating Station
| |
| ** | MCGS | Mills County Genealogical Society
| |
| ** | MCGS | Madison County Genealogical Society
| |
| ** | MCGS | Mutualist Credit Guarantee Scheme
| |
| * | MCGS | Multicultural and Gender Studies
| |
| * | MCGS | Moody County Genealogical Society
| |
| * | MCGS | Miriam College Grade School
| |
| * | MCGS | Magnetic Cash Gifting System
| |
| * | MCGS | Mobile Call Generation System
| |
| * | MCGS | Manual cover gas system
| |
| * | MCGS | Missouri Comprehensive Guidance Survey
| |
| * | MCGS | Milwaukee County Genealogical Society
| |
| * | MCGS | Moore County Genealogical Society
| |
| * | MCGS | Marin County Genealogical Society
| |
| * | MCGS | Moscow Center for Gender Studies
| |
| * | MCGS | Monroe County Genealogical Society
| |
| * | MCGS | Martin County Genealogical Society
| |
| * | MCGS | Marathon County Genealogical Society
| |
| * | MCGS | Massachusetts Computer Graphics Society
| |
| * | MCGS | Membrane coating granules
| |
| * | MCGS | Monmouth County Genealogy Society
| |