PROJECT SUMMARY/ABSTRACT In the United States, 6.5 million people have heart failure (HF), the vast majority of whom are enrolled in Medicare. Unfortunately, HF mortality is rising among Medicare beneficiaries despite significant advances in HF therapies, and evidence suggests this may be partially due to gaps in health care access and affordability. However, recent Medicare policy changes could meaningfully address these gaps, and ultimately improve HF outcomes nationwide. One major change in the Medicare program has been the rapid growth of Medicare Advantage (MA) plans, which now cover over 50% of all beneficiaries, and may be an important strategy to improve HF care. In contrast to fee-for-service (FFS) Medicare, these private insurance plans receive capitated payments from the government, and their design could impact HF patients in both beneficial and harmful ways. In Aim 1, we will determine whether health care access, affordability, and clinical outcomes differ among Medicare beneficiaries with HF enrolled in MA vs FFS Medicare, which is especially important given the substantial burden of HF in Medicare. In addition to the rapid growth in MA, the recent passage of the Inflation Reduction Act (IRA) has the potential to improve HF outcomes in Medicare. The IRA will cap annual OOP drug costs at $2000/year and expand low-income subsidies for Medicare beneficiaries, which could have major implications for those with HF. In Aim 2, we will use quasi-experimental approaches to determine whether the IRA leads to real-world changes in OOP costs and associated improvements in medication adherence and outcomes for Medicare beneficiaries with HF. Data on the real-world impact of the IRA will be critical as policymakers consider strategies to improve HF outcomes in Medicare. Finally, as enrollment in MA continues and the IRA is fully implemented, identifying ongoing and/or new barriers to HF care in Medicare will be critical. In Aim 3, we will use semi-structured interviews of Medicare beneficiaries with HF and clinicians to identify barriers in care access, affordability, and GDMT adherence, and novel strategies to address them. Qualitative results from these interviews will serve as preliminary data for future studies that test and implement new interventions to improve HF outcomes in Medicare. The overarching goal of this proposal is to use Medicare claims, national survey, and qualitative data combined with advanced statistical methods to evaluate the impact of new Medicare policies on the millions of beneficiaries with HF, and to identify emerging barriers to care in this population. I will perform this work in the setting of a comprehensive career development plan designed to provide me with the experience and skills necessary to become an independent research scientist. My long-term career goal is to use mixed methods to evaluate how policies and interventions impact care delivery and outcomes for HF patients, and I will use the research and sk...