Optimal diabetes management benefits from a team-based approach involving primary and specialty endocrinology care, particularly for older adults with multimorbidity and clinical complexity (1). Primary care and endocrinology services are associated with improved diabetes outcomes (2), though reliance on endocrinology care may be greater for older adults with type 1 diabetes (T1D), due to considerations of advanced diabetes technology use. People living in rural or high-deprivation areas often have limited access to quality diabetes care (2,3), potentially contributing to worse outcomes. National patterns of primary care and endocrinology use by older adults with T1D and type 2 diabetes (T2D) in the U.S. remain poorly characterized. This longitudinal study used a 20% random sample of 2017-2021 Medicare fee-for-service (FFS) claims linked to 2020 Reproducible Area Deprivation Index (ReADI) data via a ZCTA-5-digit ZIP crosswalk data file. Outcomes were evaluated annually from 2018 to 2021; baseline covariates were measured in the prior years (2017-2020). The final sample included individuals aged u226565 years with T1D or T2D and 12 months of continuous Medicare Parts A and B enrollment at baseline. Outcomes were binary annual indicators of having one or more primary care or endocrinology encounters, defined using outpatient evaluation and management, telehealth, and care management Current Procedural Terminology codes (Supplementary Table 1). Covariates included age, sex, race and ethnicity, heart failure, cancer, chronic pulmonary disease, chronic kidney disease kidney failure, cardiovascular disease, cerebrovascular disease, peripheral vascular disease, retinopathy, lower extremity amputation, dual eligibility, year, and ReADI quintiles. ReADI is a composite measure of arealevel socioeconomic factors (4).