PROJECT SUMMARY One in six people in the United States have infertility, which is treated most effectively with in vitro fertilization (IVF). IVF is a powerful therapy that requires careful decision-making by patients to balance the risks of IVF with the chances of having a healthy live birth. The most consequential decision during IVF is about the number of embryos to transfer into the uterus. Transferring multiple embryos improves the chances of a birth, but it also increases the likelihood of multiple births, which are risky for mothers and infants. Historically, health insurance excluded coverage for IVF, but employers have been rapidly expanding IVF coverage as they compete for employees. Employers are creating these new IVF benefits with little research evidence to guide them. Poorly designed IVF benefits could cause more harm than good by inadvertently incentivizing multiple embryo transfers and multiple births or by delaying care. Our preliminary research found that IVF benefit designs range from generous (e.g., covering multiple IVF cycles) to meager (e.g., a lifetime cap of $5,000 when IVF costs $15,000 per cycle) and that cost is a top concern for patients. Much remains unknown about how to design safe, high-quality IVF benefits. The investigators’ long-term goal is to generate compelling new evidence that can improve the design of IVF benefits and therefore promote the health of parents and infants. The central hypothesis is that IVF benefit design influences patients’ decisions during IVF and thus affects their health outcomes. The rationale for this project emerges from the rapidly shifting landscape of IVF coverage across the US, which is outpacing a scant research evidence base. The central hypothesis will be tested by completing three Specific Aims: (1) Define the characteristics of employer-sponsored IVF insurance coverage in the US; (2) Quantify which elements of insurance coverage for IVF most influence patient decision-making during IVF; and (3) Evaluate the health outcomes and medical expenditures associated with nine different IVF benefit designs. This study will be completed using a multi-method approach that unites systematic, nationwide evaluations of the characteristics of IVF benefit designs, a sophisticated survey of patient decision-making under different IVF benefit designs, and an analysis of real- world patient outcomes and medical expenditures under nine employers’ different IVF benefit designs. With these data, we will be able to measure real-world health outcomes and medical expenditures after IVF, predict health outcomes for mothers and infants for a range of IVF benefit designs grounded in existing coverage nationwide, and advise employers and policymakers on how to create IVF benefits that promote maternal and infant health and avoid unintended negative outcomes. The research is innovative because it will define the characteristics of IVF coverage in the US for the first time and quantify which elements of i...