PrecivityAD2 is an FDA-cleared blood test for adults 40 and older with signs of cognitive impairment being evaluated for Alzheimer's or other decline. For people with mild cognitive impairment, or MCI, it gives doctors a blood-based aid that looks for amyloid buildup alongside exams and thinking tests. NeurologyLive reported the Aug.
20, 2026 clearance in its FDA clearance report. MCI means you notice memory or thinking changes, but you still manage daily tasks on your own. This briefing explains who fits the test, what scores mean, and what to ask next.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- Who fits the test in 2026?
- What does the blood sample show?
- How accurate is it for MCI?
- What are the limits?
- How do you arrange testing?
Who fits the test in 2026?
The test is for symptomatic adults, not for routine screening. NeurologyLive described it as the first FDA-cleared Alzheimer's blood test authorized down to age 40 and the third cleared blood-based option.
That matters for early-onset concerns and for people whose prior age cutoffs blocked testing. Ask your doctor about testing if you match this picture: Bring examples of changes, medicines, sleep issues, and family history to that visit. A clinician can rule out other causes before ordering amyloid testing.
- age 40 or older with ongoing memory, language, or thinking symptoms
- a clinician is already evaluating you for Alzheimer's or other decline
- you have MCI findings on history, exam, or cognitive testing
What does the blood sample show?
NeurologyLive explained the lab method uses high-resolution mass spectrometry to measure two plasma signals. One is amyloid-beta 42 over 40, and the other is percent p-tau217 over non-p-tau217. Software combines them into the Amyloid Probability Score 2, reported as negative, positive, or intermediate likely positive. Amyloid refers to sticky protein clumps linked to Alzheimer's brain change.
NeurologyLive reported validation in a 1,142-person symptomatic group compared with amyloid PET or spinal fluid tests. Positive results matched pathology in 97.6 percent of cases. Negative results matched absence of pathology in 93.1 percent of cases. About 17.3 percent fell in the likely-positive middle group, where 77.3 percent had amyloid pathology.
How accurate is it for MCI?
A separate peer-reviewed study focused on people with MCI or dementia and compared the blood test with amyloid PET. C2N Diagnostics summarized it as 91 percent accuracy, with 90 percent sensitivity and 92 percent specificity, in its research summary. The team used the CLIA cutoff already in clinical use.
That means the test caught most amyloid-positive cases and cleared most amyloid-negative cases in that group. It still leaves errors on both sides, so doctors pair the score with exams, history, and thinking tests. For MCI, a positive score points toward amyloid as a driver, while a negative score points away.
What are the limits?
The test aids detection of amyloid pathology, but it does not diagnose Alzheimer's alone. Practical Neurology stressed it must be used alongside clinical history, exam, and cognitive testing in its Alzheimer's testing update.
It is not meant for people without symptoms and not as a standalone diagnosis. Treat middle or positive scores as next-step signals, not final answers: Bring all prior brain scans, lab work, and cognitive scores to follow-up. Ask what added testing would change for treatment or planning.
- a likely-positive result still carries uncertainty and needs clinical follow-up
- a positive result still needs history, exam, and cognitive context
- no symptoms means no indication for this test
How do you arrange testing?
In 2026, most people reach the test through C2N's existing licensed lab rather than a kit at a local lab. Medical News Today noted the FDA-cleared kit version was expected later in 2026 in its 2026 access overview. Use these steps with your care team: Keep the printed score with your medication list for every specialist visit.
- confirm MCI with a visit, exam, and scored thinking test
- ask whether amyloid testing fits your history and goals
- review the score category and decide on added scans or referrals
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