Disclosed are a method and an algorithm for genetic cross-matching based on the comparison of recipient and donor genotypes--and the underlying combinations of alleles and haplotypes. The method of the invention, rather than focusing on phenotype prediction, instead relies on a comparison of genetic variants identified in the recipient and available donors, whose information preferably will be compiled in a widely available donor registry, to maximize molecular compatibility. The genotypes can be matched based on the weighted clinical significance of a genotypic difference between donor and recipient, such that certain mismatches are more acceptable than others.