Patients with leukemia and other blood diseases stand a good chance of recovery and a return to normal life if they receive a stem cell transplant from a living donor. In the absence of a transplant, their survival prospects are grim. For a transplant to be successful, the human leukocyte antigens (HLA) of the donor and recipient must be a close genetic match. To facilitate non-sibling matches, the developed nations of the world have set up national volunteer registries. The larges such registry is the NMDP (National Marrow Donor Program). We estimate the distribution of HLA types for individuals of mixed race and calculate probabilities that persons of each specified mixed-race combination will find a match in the current NMDP registry. We use these statistics to estimate the expected number of lives saved from adding a person of specified race or mixed-race combination to the registry. Using standard economic estimates of the value of a statistical life, we estimate a dollar value of adding registrants of any specified race or mixed race.