| Abbreviation | Definition |
|---|---|
| ABA | Austrian Business Association |
| ABAA | Antiquarian Booksellers' Association of America |
| ABAC | Antiquarian Booksellers Association of Canada |
| ABAC | APEC (Asia Pacific Economic Cooperation) Business Advisory Council |
| ABAG | Association of Baltimore Area Grantmakers |
| ABAI | American Board of Allergy and Immunology |
| ABAME | American Board of Aviation Medical Examiners |
| ABAN | Arab Business Angel Network |
| ABAP | American Board of Assessment Psychology |
| ABC | Afghan Beijing Corps |
| ABCFP | Association of BC Forest Professionals |
| ABCP | American Board of Certification in Prosthetics |
| ABCPO | American Board for Certification in Prosthetics and Orthotics |
| ABCU | Association of Burroughs Computer Users |
| ABD | Association of British Drivers |
| ABDO | Association of British Dispensing Opticians |
| ABEM | American Board of Electrodiagnostic Medicine |
| ABEM | American Board of Emergency Medicine |
| ABEM | American Board of Environmental Medicine |
| ABES | American Board of Eye Surgery |