Searching for a Match

If you need an allogeneic transplant, the cells you receive will come from someone else. Your doctor will look for a donor who:

1. Is available – The best donor may be the person that’s available to donate when you need a transplant.
2. Closely matches your human leukocyte antigens, or HLA, type – These are markers your body uses to know which cells belong in your body and which don't. To look for a donor, your doctor may test your family and look for a donor or cord blood unit.
3. Is younger than 31 years old – Patients tend to do better after transplant with a donor younger than 31 years old. 

Your doctor may test your family members because you inherit HLA markers. Each of your siblings who share the same biological parents as you have a 1 in 4 chance of being a full match. However, most patients do not have a close match in their family and need a transplant from someone else or a donated umbilical cord.

The registry of the C.W. Bill Young Cell Transplantation Program, also called the NMDP Registry^SM, is a listing of potential marrow donors and donated cord blood units. The registry is operated under Federal contracts by the NMDP^SM. NMDP has agreements with its global partners to provide access to more than 43 million potential marrow donors and more than 750,000 cord blood units within its search system.*

*Updated as of February 2026. Current numbers can be found at World Marrow Donor Association.

Find more information about how your doctor finds a donor.

Learn how patients who need a transplant are being given hope by NMDP.

It can take a few weeks to a few months or more to find a marrow donor or cord blood unit. However, sometimes a suitable marrow donor or cord blood unit cannot be found. If your doctor cannot find a donor for you, they will look at other treatment options.

Sometimes, family and friends want to help by adding more donors to the registry. NMDP can help with donor recruitment efforts.

Host a Donor Drive