| A/CH | Alternate CHannel 
| Others |
| ACH | A Child's Hope
| Others |
| ACH | A Crack Head
| Others |
| ACH | Absorption Chiller Heater
| Others |
| ACH | Academy of Communication in Healthcare
| Others |
| ACH | Access Feedback Channel
| Others |
| ACH | Accessible Coat Hooks
| Others |
| ACH | Account Clearing Hacking
| Others |
| ACH | Account Clearing House
| Others |
| ACH | Accountable Community of Health
| Others |
| ACH | ACCS Common Hardware
| Others |
| ACh | Acetylcholine
| Others |
| ACH | achalasia
| Others |
| ACH | achondroplasia
| Others |
| ACH | Acoli
| Others |
| ACH | ACTH, adrenocorticotropic hormone
| Others |
| ACH | Active Chronic Hepatitis
| Others |
| ACH | Acute Care Hospital
| Others |
| ACH | AdrenoCortical Hormone
| Others |
| ACH | Advanced Combat Helmet
| Military, Air Force, Army, Defence, Special Forces, Hardware, Safety |
| ACH | Air Change per Hour
| Others |
| ACH | Air Changes per Hour
| Others |
| ACH | Air Craft Hand
| Others |
| ACH | Airbus Corporate Helicopters
| Others |
| ACH | Airlines Clearing House
| Others |
| ACH | Aki, Christoffersson, and Husebye
| Others |
| ACH | Alcohol Childish Hurt
| Others |
| ACH | Allergic Contact Hypersensitivity
| Others |
| ACH | Altenrhein, Switzerland
| Others |
| ACH | American College of Healthcare
| Others |
| ACH | Analysis of Competing Hypotheses
| Others |
| ACH | Anno Concordia Humanus
| Others |
| ACH | Arkansas Children's Hospital
| Others |
| ACH | Associated Channel Header
| Others |
| ACH | Association for Computers and the Humanities
| Others |
| ACH | Auckland City Hospital
| Others |
| ACH | Austin Club Holland
| Others |
| ACH | Australian Camp Hospital
| Others |
| ACH | Auto Check
| Others |
| ACH | Autoliv China Headoffice
| Others |
| ACH | Automated Check Handling
| Others |
| ACH | Automated Clearing House
| Others |
| ACH | Automatic Clearing House
| Others |
| ACH | Automobilski Cluster Hrvatske
| Others |
| ACH | Automotive Components Holdings
| Others |
| ACH | Autos Clasicos e Historicos
| Others |
| ACH | Auxiliary Heater
| Others |
| ACH | St. Gallen-Altenrhein Airport
| Others |