Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) for ∼20 years prior to dementia onset. Phthalates, routinely added to plastics to increase flexibility, and bisphenol monomers, have been shown to interfere with neural activity/brain function. Phthalate and bisphenol exposure did not show association of individual urinary biomarkers with Aβ or clinical phenotype (mild cognitive impairment (MCI)/AD). Assessing biomarkers in quartiles, low mono(2-ethylhexyl) phthalate (MEHP), but not other biomarkers of di(2-ethylhexyl) phthalate (DEHP), was associated with Aβ+ and with having MCI/AD (q < 0.05), while high Bisphenol S (BPS) was associated with Aβ+ (q < 0.05). Mixture analysis shows significant association with MCI/AD but not Aβ.