Unintended pregnancies resulted in $21 billion in avoidable health care costs in the United States as of the most recently available data in 2010 and are associated with myriad negative health effects for mothers and children. They disparately impact vulnerable groups of women, such as those 18-29 years old, Black women, low-income women, single women, and less educated women. A medication abortion is one method of terminating a pregnancy which is over 95% effective, safe (with major adverse events in less than 0.5% of cases), has minor side effects, and costs less than 20% of a live birth.However, states have different levels of medication abortion utilization: in 2020, percentages ranged from 13.7% in Missouri to 96.6% in Wyoming in 2020. The FDA’s abortifacient protocol is more restrictive than medically necessary to ensure women’s safety. For example, although the FDA expanded medication abortions for use up to ten weeks of gestation in 2016 from the previous seven-week limit, studies show safety and efficacy beyond ten weeks of gestation. Many states have laws which restrict access to medication abortions beyond their laws that restrict access to all abortions. Additionally, many states have laws that regulate access to medication abortions more strictly than the FDA. These laws can result in a delay in obtaining abortion care, possibly past the FDA’s ten-week limit for medication abortions, which could make the patient ineligible for a medication abortion in some states. A state’s percentage of medication abortion utilization may depend upon which law(s) that state has in place restricting access. This is the first study to examine that relationship. There is a gap in the literature as to why medication abortion is underutilized given that a majority of abortions occur within the FDA’s ten-week time limit and that the majority of women who received an abortion would have preferred to receive it earlier than they did. The goal of this dissertation is to examine the impact of certain laws restricting medication abortion access on medication abortion utilization in states with such laws in place as compared to states without such laws in place. The aims of the proposed dissertation were threefold. Study one examined medication abortion utilization among women who obtained abortions in states with laws that restrict public and/or private insurance coverage of abortion as compared to states with no insurance coverage restrictions from 2010 to 2019. It was expected that restricting public and/or private insurance coverage of abortion would be statistically significantly associated with lower state medication abortion utilization as compared to states without public and/or private insurance coverage restrictions. Study two examined medication abortion utilization among women who obtained abortions in states that required both in-person physician involvement prior to the abortion and that the first dose be administered in person in the presence of a physician and states with only one physician involvement requirement as compared to states with neither physician involvement requirement from 2010 to 2019. It was expected that state laws requiring either or both in-person physician involvement prior to the abortion and/or that the first dose be administered in the presence of a physician will be statistically significantly associated with lower medication abortion utilization as compared to states requiring no in-person physician involvement. Study three examined medication abortion utilization among women who obtained abortions in states that require both in-person physician involvement prior to the abortion and that the first dose be administered in person in the presence of a physician and states with only one physician involvement requirement as compared to states with neither physician involvement requirement, adjusting for the percentage of women aged 15-44 living in counties without an abortion provider in 2017. It was expected that state laws requiring either or both in-person physician involvement prior to the abortion and/or that the first dose be administered in the presence of a physician would be statistically significantly associated with lower medication abortion utilization as compared to states requiring no in-person physician involvement, adjusting for the percentage of women aged 15-44 living in counties without an abortion provider in 2017. We used multiple imputation of data in all three of our studies, linear mixed model analyses in the first two, and a regression analysis in the third. While our studies did not uncover any statistically significant associations between the laws examined alone and medication abortion utilization, there were some statistically significant secondary findings. All three of our studies found states with higher percentages of patients who were at least ten weeks pregnant at the time of their abortions to be associated with lower percentages of medication abortion utilization. Our first study found that having had no previous live births was associated with a higher percentage of medication abortion utilization in states with laws restricting Health Exchange insurance plans from covering abortions, regardless of whether there were other laws restricting insurance coverage of abortion in place. Both our first and second studies found that being over thirty years of age at the time of obtaining an abortion was associated with a higher percentage of medication abortion utilization in states with at least one form of abortion insurance coverage restriction law and regardless of how many in-person physician interactions were required, respectively. These findings should guide both future research aimed at taking further steps toward understanding states’ disparate levels of medication abortion utilization as well as policymakers’ efforts at improving access to medication abortion services. / Public Health