This work evaluates Medicare Hospice Benefit (MHB) eligibility standards that are referenced throughout this work as either "Medicare prognostic criteria," or "Local Medical Review Policies." Following the Chapter 1 overview of prognosis in end-stage disease, association between the Medicare clinical predictors and survival outcomes in dementing, cardiovascular and cerebrovascular illnesses are described in Chapter 2. Chapter 3 examines the prognostic belief systems of multidisciplinary hospice personnel. Chapter 4 seeks to improve the predictive performance of the Medicare prognostic criteria for dementia. The fifth and final chapter critiques the Medicare prognostic criteria from conceptual, methodological, and applied perspectives and suggests related research and policy directions. The Chapter 2 sample comprised 453 medical records of terminally ill persons; Chapter 4 sample, 187 medical records. Thirty-seven hospice personnel comprised the respondent sample in the Chapter 3 study. Chapter 2 assesses the scientific validity of federally sanctioned Medicare "severe illness/end-stage illness" demarcations in three non-cancer disease catregories. Calculation of measures of predictive validity revealed striking and consistent imbalances of false negative and false positive errors across the three diagnostic categories studied, suggesting inequitable distribution of the costs and benefits of regulatory reform among public health payers, consumers and providers. Chapter 3 qualitatively examines the belief systems of experienced hospice personnel regarding physical and non-physical time-to-death influences in end-stage disease. Non-physical survival influences were believed by these expert informants to have more survival impact in non-cancer as opposed to cancer end-stage diseases, and at remote as compared to imminent death proximities. Chapter 3 highlights the enormous complexity of time-to-death influences as well as the importance of non-physical influences on duration of survival in end-stage disease. Chapter 4 demonstrates that dropping one of the three prognostic criteria for dementia (the medical complications criteria) may improve predictive validity. This finding demonstrates that, in dementing illnesses at least, functional debility may better identify 6-month survival prognosis and thus hospice eligibility, than the composite Medicare prognostic criteria. The merit of parsimony in objective definitions of terminality is implied. Chapter 5 critiques the Medicare prognostic criteria, and suggests policy alternatives that are both prognostically- and non-prognostically-based. Peripheral findings of this work and suggestions for future end-of-life research conclude the dissertation.