Donating bone marrow starts with joining a donor registry, which you can do from home with a free cheek swab kit. From there, you stay on the registry until you’re identified as a potential match for a patient in need. The actual donation may not happen for months, years, or ever, but when it does, the process is straightforward and costs you nothing out of pocket.
Joining the Donor Registry
The national registry in the United States is managed by the NMDP (formerly Be The Match). You can join online by answering a few health questions, then requesting a free swab kit mailed to your home. It typically arrives in 3 to 7 days. You swab the inside of your cheeks following the kit’s instructions, then mail the samples back in a prepaid envelope. The lab processes your tissue type and adds it to the registry, where it can be compared against patients searching for a match.
After that, you wait. Matching is complex and depends on specific proteins on your cells aligning closely with a patient’s. Some donors are contacted within weeks; others wait years or are never called. The most important thing you can do once you’re registered is keep your contact information current so you can be reached if a match comes up.
Who Can Register
You need to be between 18 and 60 to join, but the registry prioritizes recruiting people ages 18 to 35. Medical research shows younger donors provide the greatest chance of transplant success, and doctors consistently prefer donors in that age range. You also need to be in generally good health. Conditions like heart disease, diabetes, or hepatitis can disqualify you, either at the time of registration or later if your health changes while you’re on the registry.
Why Diverse Donors Matter
Matching depends on inherited tissue markers, which means your best chance of matching someone often comes from people who share your ethnic background. Non-Hispanic white patients are statistically more likely to find a high-quality match on the registry compared to other racial and ethnic groups. Every patient has at least one potential donor at lower match thresholds, but at the highest match levels, only about 52% of patients find someone. Registries need more donors from underrepresented backgrounds to close that gap.
The Two Types of Donation
If you’re called as a match, your doctor and the patient’s medical team will determine which of two collection methods is best. You don’t always get to choose, but both are well-established procedures.
Peripheral Blood Stem Cell (PBSC) Donation
This is the more common method. It’s a nonsurgical, outpatient procedure. For five days before collection, you receive daily injections of a medication that pushes blood-forming stem cells out of your bone marrow and into your bloodstream. The most common side effect of these injections is bone pain, which affects roughly 30% of donors. Headache and mild fever are also possible. These side effects typically disappear within a couple of days after the injections stop.
On collection day, you sit in a chair while blood is drawn from one arm, passed through a machine that filters out the stem cells, and returned through your other arm. A single session can take up to eight hours. If two sessions are needed on separate days, each runs four to six hours.
Surgical Bone Marrow Donation
This is a hospital procedure done under anesthesia. About 96% of donors receive general anesthesia, meaning you’re completely unconscious. The remaining donors get regional anesthesia (a spinal or epidural) that numbs the lower body. The procedure typically takes 1 to 2 hours. Doctors use hollow needles to draw liquid marrow from the back of your pelvic bone through one to four small incisions, each less than a quarter inch long. No stitches are needed.
The most serious risk is related to the anesthesia itself, not the marrow collection. Afterward, you can expect tiredness, weakness, and soreness in the lower back or hip area.
Recovery After Donation
Recovery depends on which method you undergo. For PBSC donation, most people feel back to normal within a week of the collection. The bone pain and fatigue from the injections fade quickly once they stop. For surgical donation, soreness in the hip and lower back can linger for a few weeks, though many donors return to work and light activity within a week or two. Your body fully replenishes the donated marrow on its own.
Side effects from either method are temporary. Lightheadedness, chills, tingling around the mouth, or hand cramping can occur during or shortly after PBSC collection but resolve quickly. Long-term health effects for donors are not a significant concern.
What It Costs You
Nothing. There is no cost to sign up for the registry, and there is no cost to donate. The patient’s insurance covers the donation procedure, related testing, and medical appointments. Organizations like DKMS and the NMDP also cover transportation costs to get you to the collection center. If travel and lodging are needed, those expenses are reimbursed as well. You won’t receive a bill for any part of the process.
What Happens After You’re Called
Being identified as a potential match kicks off a series of steps before you ever reach a collection center. You’ll have additional blood tests to confirm the match, a physical exam, and an information session where the medical team walks you through exactly what to expect. The entire timeline from initial contact to donation day is usually several weeks, giving you time to prepare and ask questions.
One thing the registry emphasizes: commitment matters. A patient preparing for a transplant undergoes intensive treatment to destroy their existing marrow before receiving yours. If a donor backs out late in the process, the patient is left in a life-threatening situation with no functioning immune system and no replacement cells. Once you agree to move forward, following through is critical.