Indiana University-Purdue University Indianapolis (IUPUI) / Medicaid covers 21% of Americans which includes over 65 million children and adults, making it the largest single source of health insurance for Americans. As a public program jointly administered between the federal and state governments, states exhibit substantial control over the structure of their programs, with the intention of modifying programs to fit the needs of the state and population. Medicaid has experienced numerous changes at both the state and federal levels in recent years which have created novel ways of modifying their structures, many of which may have implications for administrative expenditures. As publicly funded programs and given the state autonomy over such, it is important to consider the relationships and effects of such decisions on the performance of these programs. The purpose of this dissertation is to consider numerous variations in state Medicaid programs and the state contexts in which they operate, and the relationship to administrative spending. This dissertation focuses on three studies including 1) a panel analysis of the trends and correlates of state Medicaid administrative expenditures, 2) a quasi-experimental study of the effects of Medicaid expansion on administrative expenditures, and finally 3) a quasi-experimental study of the effects of the use of Express Lane Eligibility on administrative expenditures. Overall, this dissertation provides a better understanding of the variations, correlates, and drivers of Medicaid administrative expenditures.