Quick answer
AB positive (AB+) is the universal red blood cell recipient under the ABO and RhD systems. AB+ people carry A, B and RhD antigens, so their plasma contains no anti-A, anti-B or anti-D antibodies to react against donor red cells, and they can receive red cells from all eight ABO/Rh types. Compatibility still depends on other blood group systems and crossmatching. For plasma, type O is the universal recipient.
AB positive vs AB negative: which donors match?
| Recipient | Compatible red cell donors |
|---|---|
| AB positive (AB+) | O−, O+, A−, A+, B−, B+, AB−, AB+ |
| AB negative (AB−) | O−, A−, B−, AB− |
AB− is not a universal recipient across Rh types. For plasma, the direction reverses: type O is the universal ABO plasma recipient, while AB recipients generally receive AB plasma.
Compare a specific donor and recipient
See whether two types match under standard red cell or plasma rules, with an explanation.
Why AB positive can receive from anyone
Your immune system only makes ABO antibodies against the A or B antigens you lack. An AB+ person has both A and B antigens and is RhD-positive, so they do not carry anti-A, anti-B or anti-D. Within the ABO and RhD systems, that means a donor's A, B or RhD antigens have nothing to react against—though antibodies to other blood group systems can still matter, which is why crossmatching continues.
| Recipient | Can receive red cells from |
|---|---|
| AB+ | O−, O+, A−, A+, B−, B+, AB−, AB+ (all types) |
What this means in practice
In practice, hospitals still give AB+ patients type-specific or closely matched blood when it is available, reserving the flexibility for shortages. AB+ is a relatively uncommon type, around 3 percent of the U.S. population, so AB+ patients benefit from being able to draw on the far larger supply of O and A blood.
Limits of the label
As with the universal donor, “universal” refers only to ABO and RhD. Antibodies to other blood group antigens (for example Kell or Duffy) can develop after previous transfusions or pregnancies, and a crossmatch is still performed whenever time allows.
The universal plasma recipient is O
For plasma the logic reverses. Type O red cells carry no A or B antigens, so no donor plasma's antibodies can attack them; O recipients can receive plasma from any ABO type. AB recipients, meanwhile, can only receive AB plasma. See the plasma compatibility guide.