Older individuals overwhelmingly prefer to receive long-term services and supports (LTSS) in home and community-based settings. Medicaid elderly 1915(c) waivers have become the primary mechanism that states use to provide home and community-based services (HCBS) to older individuals. Given the positive effects elderly waivers have on the quality of life of older individuals, I examined why states adopt elderly waivers; the extent of the substantive differences in program quality across elderly waivers; and the factors associated with elderly waiver program quality, contrasted with the factors associated with elderly waiver program size (i.e., number of participants and expenditures). I examined how state contextual, institutional, and political factors, as well as factors external to the states, including neighboring state and federal policy activity, influenced state policy decisions pertaining to elderly waiver adoptions and program quality and size. First, I performed a retrospective analysis using state-level longitudinal data from 1992-2010 to conduct a discrete time-series repeated event history analysis (EHA) to identify the variables associated with state adoptions of elderly waivers. Second, I created a measure of elderly waiver program quality consisting of four equally weighted components of waivers thought to be associated with the provision of higher quality HCBS to older individuals, including: eligibility criteria, self-determination supports, range of services provided, and participant protections. Using correlational analyses, I examined the relationships between program quality and size. Third, I performed retrospective ordinary least squares (OLS) analyses using waiver program-level data from 2015 to examine elderly waiver program quality and size and fixed-effects OLS using data from 1993-2010 to examine elderly waiver program size. I identified 63 elderly waiver adoptions across 35 states between 1992 and 2010, which were significantly associated with state contextual and external factors. Consistent with previous research, I found that contextual factors, including the number of older individuals, the supply of long-term care facilities and whether the state already had an elderly waiver program, affected state decisions to adopt elderly waivers. There was significant variation in each of the four component and overall quality scores and weak associations between program quality and size. I found that state contextual factors, including market and Medicaid program characteristics, influenced elderly waiver program quality and size. In addition, program quality was shaped by the capacity of state policymaking institutions (e.g., governorships and legislatures), while program size was shaped by neighboring state and federal policy activity. The findings from this research suggest that elderly waiver adoptions and program quality and size are shaped through different policymaking pathways. Efforts to improve the quality of elderly waiver programs should consider the capacity of state executive officials in addition to contextual determinants and focus on improving existing elderly waiver programs. Given that most waivers scored well on eligibility and participant protections, efforts to improve the quality of elderly waiver programs should focus on expanding self-direction supports opportunities, the types of waiver services, and eliminating restrictions placed on service delivery (e.g., waiting lists).