The FDA cleared PrecivityAD2, a blood test that helps diagnose Alzheimer's disease, on August 20, 2026, so the title's premise is confirmed. But "cleared" is narrower than it sounds: before you or a relative treats this test as an answer, verify five things — who it's for, what it actually measures, its limits, how you get it, and what the result really means. PrecivityAD2 is a laboratory blood test from C2N Diagnostics that estimates whether amyloid plaque, a hallmark of Alzheimer's, is building up in the brain. This article walks through what to confirm before you rely on it, using the clearance documents and the peer-reviewed validation behind them.
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.
Official resources:
- Read the official guidance from Washu — Use this primary source to verify the official guidance.
- Check eligibility on Alz’s official study page — Use this page to check the study’s participation requirements.
Table of Contents
- What the FDA actually cleared
- Is this test right for the person in front of you?
- What it measures, and what "over 90% agreement" leaves out
- How to get it, and questions to ask
- Checking the claims yourself
- Frequently Asked Questions
What the FDA actually cleared
The FDA clearance announced by C2N Diagnostics covers PrecivityAD2 as an aid in diagnosing Alzheimer's in adults aged 40 and older who already show signs or symptoms of cognitive impairment. That age floor is the headline: according to NeurologyLive, it is the first FDA-cleared Alzheimer's blood test available to symptomatic patients as young as 40, and the third such blood test the agency has cleared. The word to weigh is "aid." The Alzheimer's Association states the test is cleared only as one input used alongside a clinical evaluation by clinicians experienced in cognitive assessment.
It is explicitly not a screening test and not a standalone diagnosis. So the first thing to verify is framing. A positive result does not by itself mean a person has Alzheimer's, and a clinician still drives the diagnosis.
Is this test right for the person in front of you?
Eligibility is the second thing to confirm, and it is stricter than many hopeful readers expect. Per Patient care Online, the clearance covers people who are already presenting cognitive symptoms — not healthy adults who feel fine but want early or predictive screening.
Check these before raising it with a doctor: If someone is asymptomatic and simply worried about family history, this is not the cleared use. A worried-but-well adult asking for a "peek" falls outside what the FDA reviewed, and a result in that setting carries no validated meaning.
- The person is 40 or older.
- They already have signs or symptoms of cognitive impairment, such as memory or thinking changes.
- They are working with a clinician who can order the test and interpret it in context.
What it measures, and what "over 90% agreement" leaves out
Third, verify what the number actually reflects. According to WashU Medicine, PrecivityAD2 uses high-resolution mass spectrometry — a precise lab method for measuring molecules — to read the plasma amyloid-beta 42/40 ratio and a form of phosphorylated tau (%p-tau217). A proprietary algorithm, the Amyloid Probability Score 2, combines them to flag brain amyloid linked to Alzheimer's.
Performance is strong but not absolute. In the validation published by Meyer and colleagues in Alzheimer's & Dementia, the combined algorithm reached over 90% agreement with amyloid PET scans or spinal-fluid testing at a single cutoff. The catch to verify per patient: a share of people — roughly 9.6% to 17% across studies — land in an intermediate or "likely positive" zone where the result is inconclusive. For those patients, the blood test does not settle the question and further testing is needed.
How to get it, and questions to ask
Fourth, confirm access. PrecivityAD2 is a physician-ordered laboratory test, offered through C2N and, per the Mayo Clinic Laboratories catalog, through Mayo.
You cannot self-order it; a clinician must request it. When the topic comes up at an appointment, ask: Ask about cost directly, because FDA clearance does not guarantee insurance coverage.
- Given these symptoms, will the result change what we do next?
- If the score comes back intermediate, what is the follow-up plan?
- How does this fit with the rest of the cognitive workup?
- What will it cost, and is it covered?
Checking the claims yourself
Fifth, you can look past the company's own statements. The clearance built on a prior FDA regulatory filing, and independent validation has been published, including work posted on medRxiv.
That lets a careful reader or clinician cross-check the test's performance against peer-reviewed data rather than marketing alone. That habit matters most with a symptom as frightening as memory loss. A test that is accurate for the population it was studied in can still return an inconclusive result for one individual, which is exactly why the clearance keeps a clinician in the loop.
Frequently Asked Questions
Does a positive PrecivityAD2 result mean I have Alzheimer's?
No. The Alzheimer's Association notes it is an aid, not a standalone diagnosis; it flags amyloid, and a clinician interprets it with the full evaluation.
Can I order the test without a doctor?
No. Mayo Clinic Laboratories lists it as a physician-ordered test, so a clinician must request it.
What happens if my score is "intermediate"?
The result is inconclusive. Studies put this group at about 9.6%–17% of patients, and they need further testing to resolve the question.
