Insurance companies use minimum volume requirements as one criterion for selecting which hospitals to designate as high quality care providers, often termed “Centers of Excellence.” This practice is common for many complex surgical procedures, including organ transplants. The empirical literature, however, has found mixed results from better outcomes at high volume hospitals to better outcomes at mid-sized hospitals to no correlation at all between outcomes and annual volume. Further evidencing the lack of a clear relationship between annual volume and outcomes, minimum volume requirements used by insurance companies exhibit extensive variation with, for example, thresholds ranging from 3 kidney transplants per year (Medicare) to 60 kidney transplants per year (Aetna). The unique constraints of organ transplantation make using unnecessarily high annual volume requirements particularly dangerous.  Cadaveric donor organs have a shelf-life of approximately 6 hours for hearts and lungs, 12 hours for livers, and 24 hours for kidneys, which requires that patients and donor organs arrive at the transplant center and are prepped for surgery within that short time frame. Restricting the number of transplant centers means that many patients, especially the financially constrained, will not be able to receive a life-saving transplant simply because no transplant center is located sufficiently close by. This paper shows that no annual volume-outcome relationship exists for kidney and liver transplants, the two most common types of transplants performed. For the thoracic organ transplants, a volume-outcome relationship does exist. (These results persist across a wide range of functional forms, and instrumental variable techniques indicate that selective referral is not confounding the relationship between annual volume and post-transplant survival.) Therefore, the tradeoff between better post-transplant survival outcomes and reduced access to transplantation may be reasonable for hearts and lungs, but for kidneys and livers, such insurer requirements are only patient welfare-reducing in that they restrict access with no associated benefit from improved outcomes.