PrecivityAD2 is a blood test that helps doctors evaluate adults who already have symptoms of cognitive decline — and as of August 2026, it can be used in patients as young as 40. The FDA cleared the test on August 20, 2026 as an adjunct aid for evaluating Alzheimer's disease in adults 40 and older who present with signs of cognitive impairment, made by C2N Diagnostics.
For families watching a parent, spouse, or sibling develop memory or thinking problems well before typical retirement age, this is the first FDA-cleared Alzheimer's blood test that reaches down into that younger age range. Earlier cleared and lab-developed versions started at 55 or 50, which meant a 42-year-old with concerning symptoms had no comparable blood-based option. The Alzheimer's Association said extending clearance to age 40 was a direct response to the reality that younger-onset Alzheimer's affects many families.
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
- What Does the Test Actually Measure?
- How Reliable Are the Results?
- Why Does Age 40 Matter for Younger-Onset Families?
- Where Can Families Actually Get This Test Right Now?
- What About Insurance Coverage?
- Frequently Asked Questions
What Does the Test Actually Measure?
PrecivityAD2 is a blood draw, not a scan or spinal tap. It uses mass spectrometry — a lab technique that identifies and quantifies specific proteins — to measure two ratios in plasma: Aβ42/40 and p-tau217/np-tau217, according to Practical Neurology. These are markers tied to amyloid plaque buildup, one of the biological hallmarks of Alzheimer's disease. The test combines those ratios into a single score called the Amyloid Probability Score 2, or APS2, which runs from 0 to 100.
That score sorts into three categories: Negative, Positive, or an in-between result called "Likely Positive." A clinician uses the category, alongside a full cognitive workup, to decide whether amyloid pathology is likely present and whether further testing or treatment discussion is warranted. Importantly, the test is cleared only as an adjunct — meaning it supplements a doctor's assessment rather than replacing it. NeurologyLive reported that it is explicitly not a screening tool for people without symptoms, and it is not meant to stand alone as a diagnosis. It is built for people already undergoing evaluation for cognitive symptoms.
How Reliable Are the Results?
The clearance rested on a validation study of 1,142 people comparing the blood test's results against confirmed amyloid status from PET scans or spinal fluid testing. A Positive result carried a 97.6% positive predictive value, and a Negative result carried a 93.1% negative predictive value, according to data reported by AJMC. In plain terms, most Positive and Negative results lined up with what more invasive testing would have found.
The middle category is where families should pay closer attention. "Likely Positive" results made up 17.3% of the study group, and that category's positive predictive value was only 77.3%. That gap means roughly one in four people with a "Likely Positive" result did not actually have confirmed amyloid pathology on follow-up testing.
- A Positive or Negative result is fairly dependable on its own, within the limits of any single test.
- A "Likely Positive" result is not a final answer — it signals that confirmatory testing, such as a PET scan or spinal fluid analysis, is the next step.
- None of these results function as a diagnosis by themselves; they inform the clinician's broader evaluation.
Why Does Age 40 Matter for Younger-Onset Families?
Younger-onset Alzheimer's — sometimes called early-onset — refers to symptoms that begin before age 65. It is harder to get diagnosed quickly because clinicians and families alike often rule out dementia first in someone still working or raising children. A blood test cleared only down to 50 or 55 left a gap for people in their 40s who were already showing concerning symptoms. Lowering the cleared age floor to 40 closes part of that gap.
The Alzheimer's Association's statement ties the change directly to this population, framing it as a recognition that younger-onset disease is a real and common concern, not an edge case. For a family already pursuing a cognitive workup for someone in their 40s, this test is now an option a doctor can order where it previously was not. This does not mean every person with memory concerns in their 40s should request the test. It remains tied to patients who already show signs or symptoms of cognitive impairment and are undergoing clinical evaluation — not a general wellness check.
Where Can Families Actually Get This Test Right Now?
Availability is still catching up to the clearance. The FDA-cleared version of PrecivityAD2 is expected to become available later in 2026, and until it rolls out, a separate CLIA-validated version of the same test remains available only through C2N's own clinical laboratory, according to NeurologyLive.
CLIA validation is a laboratory-quality standard distinct from FDA clearance, and it has governed access up to this point. Ask the ordering physician which version they are using and whether it's run through C2N's lab directly, since that affects both turnaround and billing.
What About Insurance Coverage?
Coverage is inconsistent and still forming. Anthem Blue Cross and Blue Shield, which covers roughly 40 million members across 14 states, began covering PrecivityAD2 starting October 1, 2026, according to CLP Magazine. That is the only confirmed major US payer coverage so far, and there is no confirmed Medicare coverage determination at this time.
Families should ask their insurer directly whether PrecivityAD2 is covered before scheduling the test, rather than assuming coverage based on the FDA clearance alone. Clearance and coverage are separate decisions made by different organizations, and a cleared test can still carry significant out-of-pocket cost without a payer policy in place. Outside the US, a Welsh health-technology assessment modeled value-based prices in the range of roughly $290 to $1,950 depending on care setting and whether the test is used for initial triage or to confirm an existing suspicion, per Health Technology Wales — a range that illustrates how much the use case affects the test's value, even though it does not reflect US market pricing.
Frequently Asked Questions
Can someone without symptoms request PrecivityAD2 just to check their risk?
No. The FDA clearance limits it to adults 40 and older who already show signs or symptoms of cognitive impairment and are undergoing clinical evaluation, not as a screening tool for healthy people.
If a result comes back "Likely Positive," does that mean Alzheimer's is confirmed?
No. That category had only a 77.3% positive predictive value in the validation study, so a clinician would typically order a confirmatory test such as a PET scan or spinal fluid analysis before drawing conclusions.
Does Medicare cover PrecivityAD2?
There is no confirmed Medicare coverage determination as of this reporting. The clearest confirmed coverage so far is Anthem Blue Cross and Blue Shield, effective October 1, 2026.
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