Summary: Pursuant to a congressional request, GAO examined organ allocation practices, focusing on: (1) the United Network for Organ Sharing's (UNOS) progress in monitoring and evaluating the impact of approved variances to the national allocation policy; and (2) the extent to which organ procurement organizations (OPO) are not considering all patients waiting when allocating organs. GAO noted that: (1) although UNOS has procedures for approving and assessing variances to the national organ allocation policy, the impact of these variances on the equitable allocation of organs is unknown; (2) in 1993, UNOS established a policy that organs should be allocated using OPO-wide waiting lists, and any deviation from this policy requires UNOS approval; (3) the policy change has resulted in a reduction in the use of specific transplant center waiting lists from 20 OPO in 1991 to only 3 in 1995; (4) UNOS has approved deviations based on geographic and demographic factors; (5) the median time patients have to wait for a kidney transplant is under 2 months, but they can wait as long as 3 years; and (6) the median time that patients wait for heart and liver transplants also varies among OPO, but is generally shorter than the waiting time for kidney transplants.