OAA |
Old Age Assistance; Older Americans Act; Opticians Association of America; oxaloacetic acid |
|---|---|
OAB |
ABO blood group; old age benefits |
OAS |
old age security; oral allergy syndrome; osmotically active substance |
OASDHI |
Old Age, Survivors, Disability and Health Insurance |
OASDI |
Old Age Survivors and Disability Insurance |