•CKM stage 4 was strongly associated with increased WMH burden at baseline, but a slower accumulation of WMH volume over time compared to earlier CKM stages.

•The association between CKM stage 4 and greater WMH burden was most evident among CN and MCI participants, but not among participants with probable AD.

•The CKM framework may enhance the identification of older adults at elevated risk for vascular-driven neurodegeneration before advanced clinical dementia manifests.