Abstract While it is well-known that healthy aging has deleterious effects on sensorimotor control, the impact of aging on sensorimotor adaptation remains controversial. We attribute the ambiguous picture that emerges from prior studies to two methodological issues. First, conventional motor adaptation tasks conflate multiple learning processes and may mask the effect of aging on component processes such as implicit recalibration or explicit re-aiming. Second, the use of limited sample sizes and tendency to treat age as a binary variable (“young” vs “old”) have made it difficult to precisely determine the impact of aging across the lifespan. The goal of this R35 research supplement addresses these issues by using novel analytical tasks that isolate implicit recalibration (Aim 1) and explicit re-aiming (Aim 2) to better understand how aging affects each learning process. To obtain a detailed characterization of how these processes evolve throughout adulthood, a large sample will be recruited using a novel web-based crowd-sourcing approach, allowing us to treat age as a continuous variable (Aim 1 & 2). Building on computational models that specify component operations underlying recalibration and re-aiming, we will investigate how aging mechanistically affects each process. In addition, we will compare natural and pathological aging by testing individuals with cerebellar degeneration in parallel experiments. In summary, this supplement will not only contribute to the parent R35 by deepening our mechanistic understanding of how natural and pathological aging of the cerebellum impact sensorimotor learning but also provide valuable open-source normative data that may inform interventions designed to improve clinical outcomes for individuals with cerebellar pathology and offset the deleterious effects of aging on motor control.