ART data are made available as part of the National ART Surveillance System (NASS) that collects success rates, services, profiles and annual summary data from fertility clinics across the U.S. There are four datasets available: ART Services and Profiles, ART Patient and Cycle Characteristics, ART Success Rates, and ART Summary. All four datasets may be linked by “ClinicID.” ClinicID is a unique identifier for each clinic that reported cycles. The Success Rates dataset contains success rates for ART cycles started during the year indicated. Since ART success depends on whether patients are using their own eggs or donor eggs, success rates are included separately for these two groups. Success rates for patients using their own eggs are shown per intended retrieval, per actual retrieval, and per transfer. These success rates are reported as cumulative success rates, which take into account transfers that occur within 1 year after an egg retrieval. Since ART success depends on whether patients are using ART for the first time or had prior ART cycles, users can examine success rates for all “Patients using their own eggs” or for “Patients with no prior ART using their own eggs.” For new patients using ART for the first time, the success rates are also shown after 1, 2, or all intended egg retrievals during the reporting year. In addition, the average number of transfers per intended retrieval and the average number of intended retrievals per live-birth delivery are shown. Success rates for ART cycles that involve the transfer of embryos created from donor eggs or donated embryos are shown and are not cumulative. They are based on donor cycles started in the year indicated that had embryo transfers, regardless of when the donor eggs were retrieved. Success rates in this section are not presented by patient age group because previous data show that an intended parent’s age does not substantially affect success when using donor eggs or donated embryos. The success rates are presented by types of embryos and eggs used in the transfer. This dataset excludes cycles that were considered research—that is, cycles performed to evaluate new procedures.