Blood Type ChartTool
Not medical advice. This site is an educational reference. For transfusions, transplants, or pregnancy care, work with a qualified clinician. In an emergency call 911 (US) or 999 (UK). This site is not affiliated with the American Red Cross, Cleveland Clinic, UNOS, or any medical institution.
AB-

AB- Blood Type

Rarest of the 8 major types - 0.6% of US donors

AB-negative is the rarest of the 8 major blood types, found in approximately 0.6% of US donors. Like AB-positive, AB-negative people produce no anti-A or anti-B antibodies and can receive red cells from any Rh-negative donor. But most critically, AB-negative plasma donors are among the rarest and most needed contributors to the blood supply - AB plasma is universally compatible regardless of Rh type.

Can donate red cells to:

2 compatible types

Can receive red cells from:

4 compatible types

What Is AB- Blood?

Antigens present

A antigen, B antigen (no Rh-D)

Antibodies produced

Anti-D only

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.

Interactive Compatibility Tool

Select your blood type:

AB-Rarest of the 8 major types - 0.6% of US donors

Can donate red cells to:

AB+AB-

2 compatible types

Can receive red cells from:

A-B-O-AB-

4 compatible types

Full AB- guide

How Rare Is AB-?

PopulationFrequency
US blood donors (Red Cross estimate)0.6%
Global population (estimate)0.9%

AB-negative is found in approximately 0.6% of US donors and about 0.9% of the global population. This makes it the rarest of the 8 common blood types. In a blood bank with 1,000 units on the shelf, you would expect fewer than 10 to be AB-negative. Blood banks must carefully manage AB-negative stocks. If you are AB-negative, your donation - whether whole blood or plasma - is extraordinarily valuable.

Clinical Notes for AB-

AB-negative individuals have both A and B antigens but lack Rh-D. From a clinical standpoint, being AB-negative means that as a recipient you can receive red cells from any Rh-negative donor (A-, B-, O-, AB-) - giving you a relatively broader Rh-negative pool compared to more restricted types like O-negative (which can only receive from O-). The dual role as both a relatively flexible recipient and a critical plasma donor makes AB-negative individuals uniquely valuable to blood banks.

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.

Pregnancy Implications for AB-

AB-negative mothers are Rh-negative. If the father is Rh-positive, the baby may be Rh-positive, creating risk of Rh sensitisation. Anti-D immunoglobulin (RhoGAM) prophylaxis is offered routinely and is highly effective. Being AB-type means your baby will inherit either A or B from you, but ABO incompatibility between mother and baby is rarely clinically significant. The key concern for AB-negative mothers is Rh status - ensure your obstetrician is aware and anti-D prophylaxis is arranged.

Full Rh factor pregnancy guide +

Organ Transplant Compatibility for AB-

AB-negative organ donors can give organs to AB-positive or AB-negative recipients only. As an AB-negative recipient, you can receive organs from A-, B-, O-, or AB- donors. This gives AB-negative patients a reasonable Rh-negative donor pool to choose from. The rarity of AB-negative blood type overall means longer wait times on transplant lists are a real possibility. Living donor evaluation is strongly recommended.

ABO compatibility for organ transplant follows the same rules as transfusion - AB- can donate organs to: AB+, 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 +

Plasma Donation for AB-

AB-negative plasma, like AB-positive plasma, is universally compatible. AB plasma contains neither anti-A nor anti-B antibodies, making it safe for any patient. AB-negative plasma donors are in extremely high demand because they are so rare. The Rh factor does not affect plasma compatibility. If you are AB-negative, plasma donation is arguably your most valuable donation - consider becoming a regular plasma donor (every 28 days).

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 +

Frequently Asked Questions about AB-

Is AB-negative the rarest blood type?
AB-negative is the rarest of the 8 common ABO/Rh blood types at approximately 0.6% of US donors. However, there are even rarer blood types outside the 8-type system. Rhnull blood (sometimes called 'golden blood') has been identified in fewer than 50 people worldwide. Bombay phenotype (h/h) affects around 1 in 10,000 people in India and is even rarer elsewhere. See our rare blood types guide for details.
Who can AB-negative receive blood from?
AB-negative can receive red cells from A-, B-, O-, and AB-. Because AB-negative people carry anti-D antibodies, they cannot receive Rh-positive blood. Within the Rh-negative pool, they can receive from all four Rh-negative ABO types (since AB-negative produces no anti-A or anti-B antibodies).
Who can AB-negative donate blood to?
AB-negative can donate red cells to AB-positive and AB-negative recipients. The A and B antigens it carries mean it can only go to people who have both these antigens (AB types). Because it lacks Rh-D, it is safe for both AB-positive and AB-negative.
Why is AB-negative plasma so valuable?
AB plasma (both + and -) is the universal plasma donor: it contains neither anti-A nor anti-B antibodies, so it is safe for any recipient. AB-negative plasma donors are especially rare. Because plasma can be donated more frequently than whole blood (every 28 days), AB-negative individuals who become regular plasma donors provide an outsized contribution to the blood supply.
Can two AB-negative parents have an O child?
No. AB-type parents both carry at least one A allele and one B allele. They cannot contribute an O allele to a child, because AB individuals do not carry the recessive i allele needed for O blood type. Children of two AB parents can be A, B, or AB, but not O.

Related Blood Types

Sources