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Blood-based biomarker testing (BBT) to detect amyloid-beta and tau is becoming part of dementia care, with likely future use in asymptomatic populations. Little is known about older adults' awareness of and experiences with BBT, or their perceptions of its potential benefits, risks, and limitations. We analyzed data from the March 2023 NPHA, a recurring nationally representative web and telephone survey of community-dwelling US adults aged 50-80. For this substudy, respondents aged 65-80 were provided a brief definition of BBT for AD and asked about: 1) their familiarity and experiences with BBT, 2) perceptions of its pros and cons, and 3) their likely responses if they tested positive. For comparative purposes, a parallel set of questions was posed about cognitive screening. Chi-square analyses assessed differences in responses to the two types of testing (BBT vs. cognitive screening), as well as demographic differences in responses to items regarding BBT (significance level p < .05). Of 1,296 respondents, 19% said they were at least somewhat familiar with BBT, with 0.6% reporting having undergone BBT. Overall, respondents were more likely to endorse test pros than cons (e.g., 76% said BBT could be useful to inform medical care or advance planning). Women were more likely than men to say they'd respond to a positive BBT result with significant distress (21% vs. 10%) and engagement in brain health behaviors (67% vs. 56%), with men more likely to endorse concerns regarding privacy of test results (38% vs. 27%). Overall, BBT beliefs were similar to those about cognitive screening, although respondents were less likely to agree that BBT should be offered annually to all older adults (51% vs. 60%) and more likely to believe a positive test result would mean they'd be likely to develop AD (74% vs. 65%). Most US older adults are not currently familiar with blood biomarker testing for AD but view it as potentially useful for informing medical care and health behaviors to reduce AD risk. Women may respond differently to BBT results than men, with future studies needed to examine the process and impact of disclosing test results.