Less common - 3.4% of US donors
AB-positive is the universal red-cell recipient. Carrying both A and B antigens plus the Rh-D antigen means the AB-positive immune system does not produce antibodies against any of these, allowing it to accept red cells from all 8 blood types. However, AB-positive can only donate red cells to other AB-positive recipients. Separately, AB is also the universal plasma donor because AB plasma contains neither anti-A nor anti-B antibodies.
Antigens present
A antigen, B antigen, Rh-D antigen
Antibodies produced
None (no anti-A, no anti-B)
Antigens are proteins on the surface of red blood cells. Antibodies are produced by the immune system against antigens it does not carry. When incompatible blood is transfused, antibodies bind to foreign antigens and trigger a haemolytic reaction.
Select your blood type:
Can donate red cells to:
1 compatible type
Can receive red cells from:
Universal recipient - can receive from all 8 types
| Population | Frequency |
|---|---|
| US blood donors (Red Cross estimate) | 3.4% |
| Global population (estimate) | 5.1% |
AB-positive is found in approximately 3.4% of US donors and about 5.1% globally. It is less common than O, A, and B types, but the rarest of the 8 major types is AB-negative (0.6%). AB types are more prevalent in East Asian populations (particularly Japan and Korea) and less common in sub-Saharan African populations. Despite its rarity, AB-positive individuals are extremely valuable plasma donors.
AB-type individuals carry both A and B antigens. Some large studies suggest AB and B blood groups are associated with modestly higher risk of venous thromboembolism compared to O. These are statistical population associations and should not influence personal medical decisions. A notable clinical point: AB-positive individuals are the only universal plasma donors. Their plasma (containing neither anti-A nor anti-B antibodies) can be given to any patient in an emergency without blood typing. Blood banks frequently need AB-positive (and AB-negative) plasma donors.
Note: Associations between blood type and disease risk are from observational studies and are not deterministic. They do not change your clinical management. Cite any specific associations with your clinician.
AB-positive mothers are Rh-positive. Rh incompatibility is not a pregnancy concern for Rh-positive mothers. Your AB blood type also means your baby will inherit at least one of A or B from you, but ABO incompatibility between mother and fetus is generally mild. If you are AB-positive and pregnant, your blood type does not add specific Rh or ABO-related risk. Your obstetrician will still test your blood type at the first antenatal visit as part of routine care.
Full Rh factor pregnancy guide +AB-positive is the universal organ recipient: organs from any of the 8 ABO types can be transplanted into an AB-positive patient based on ABO compatibility alone. However, HLA matching and crossmatch testing still matter - ABO compatibility is a necessary but not sufficient condition for transplant. As an organ donor, AB-positive can only donate to other AB-positive recipients. If you are AB-positive and want to help as a living donor, note that your compatible recipient pool is limited to AB+ patients.
ABO compatibility for organ transplant follows the same rules as transfusion - AB+ can donate organs to: AB+. However, HLA tissue matching and crossmatch testing are also required, and sensitisation from prior transfusions or pregnancies can restrict compatibility further.
Full organ transplant guide +AB plasma (both AB+ and AB-) contains neither anti-A nor anti-B antibodies. This makes AB the universal plasma donor - AB plasma can be given to any patient regardless of blood type. This is the inverse of the red-cell rule (where O-negative is universal). If you are AB-positive, plasma donation is one of your most impactful contributions to the blood supply. Plasma can be donated every 28 days, more frequently than whole blood.
Note: Plasma compatibility rules are the inverse of red-cell rules because plasma carries antibodies, not antigens. AB plasma is the universal plasma donor.
Plasma compatibility chart +