Background and Objectives: Plasma biomarkers, particularly brain-derived phosphorylated-tau (BD-p-tau) species, hold promise as screening tools for Alzheimer's disease (AD). However, their ability to reflect AD pathology remains understudied in community settings. In a community-based sample, we examined associations between plasma biomarkers and cerebral amyloid (A{beta}) deposition, and whether kidney function modified these associations. Methods: This cohort study included cognitively unimpaired, late middle-aged adults with 18F-Florbetaben PET imaging and NULISAseq-derived plasma biomarker measurements. Analyses were restricted to NULISAseq biomarkers related to AD pathology (A{beta}38, A{beta}40, A{beta}42, ACHE, BACE1, BASP1, BD-p-tau181, BD-p-tau217, CD63, IGFBP7, KLK6, MAPT-tau, PSEN1, SFRP1, total p-tau181, p-tau217, and p-tau231). As a measure of kidney function, cystatin C-based estimated glomerular filtration rate was calculated and categorized by chronic kidney disease (CKD) stage as normal/high ([≥]90 mL/min/1.73 m2); mildly decreased (60-89 mL/min/1.73 m2); and moderately/severely decreased or failure (