PURPOSE: Alzheimer's disease and related dementias (ADRD) are a significant public health concern characterized by memory decline that, over time, leads to loss of independence. This study reports ADRD diagnosis rates among Medicare beneficiaries aged ≥ 65 years in rural America. METHODS: We conducted a descriptive analysis of Medicare Fee-for-Service (FFS) and Medicare Advantage enrollees using administrative Medicare data from 2020. Combining data from Medicare FFS and Medicare Advantage produces a more complete and representative sample of older adults than previous studies that used FFS data alone. Nonmetropolitan counties were used to define rural. Rural ADRD diagnosis rates, stratified by age, sex, race/ethnicity, and Census region, were adjusted using the 2000 Census population standard. FINDINGS: The study population consisted of 54 million Medicare data Fee-for-Service (FFS) and Medicare Advantage enrollees aged ≥ 65; 5.3 million beneficiaries were diagnosed with ADRD, and 16.2% (n = 861,337) of beneficiaries diagnosed with ADRD resided in rural America. The age-adjusted ADRD diagnosis rate was slightly lower in rural America (9.6 per 100 beneficiaries) than in the United States (10.0 per 100 beneficiaries). The South Census region had the highest rural ADRD diagnosis rates. CONCLUSION: These findings underscore the need for targeted interventions and support mechanisms to address the growing burden of ADRD in rural communities.