Quick answer
AB positive (AB+) is the universal red blood cell recipient. AB+ red cells already carry A, B and RhD antigens, so AB+ plasma contains none of the antibodies that would attack donor cells. AB+ people can therefore receive red cells from all eight types. For plasma, type O is the universal recipient.
Why AB positive can receive from anyone
Your immune system only makes ABO antibodies against antigens you lack. An AB+ person has both A and B antigens and the D antigen, so there is nothing left to make antibodies against. Whatever antigens a donor's red cells carry, the AB+ recipient's plasma will not react to them.
| 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.