| OME | office of medical examiner; otitis media with effusions |
|---|---|
| OMH | Office of Mental Health |
| OMI | office of medical investigator; old myocardial infarction |
| ON | occipitonuchal; office nurse; onlay; optic nerve; orthopedic nurse; osteonecrosis; osteonectin; over... |
| OPHC | Office of Prepaid Health Care |