"During the last two decades, the treatment of infertility has improved dramatically. These treatments, however, are expensive and rarely covered by insurance, leading many states to adopt regulations mandating that health insurers cover them. In this paper, we explore the effects of benefit mandates on the utilization and outcomes of infertility treatments. We find that use of infertility treatments is significantly greater in states adopting comprehensive versions of these mandates. While greater utilization had little impact on the number of deliveries, mandated coverage was associated with a relatively large increase in the probability of a multiple birth. For relatively low fertility patients who responded to the expanded insurance coverage, treatment was often unsuccessful and did not result in a live birth. For relatively high fertility patients, in contrast, treatment often led to a multiple, rather than a singleton, birth. We also find evidence that the beneficial effects on the intensive treatment margin that have been proposed in other studies are relatively small. We conclude that, while benefit mandates potentially solve a problem of adverse selection in this market, these benefits must be weighed against the costs of the significant moral hazard in utilization they induce"--National Bureau of Economic Research web site.