On Aug. 20, 2026, FDA cleared C2N Diagnostics' PrecivityAD2 blood test for adults age 40 and older with signs of cognitive impairment. According to NeurologyLive, it is the first FDA-cleared Alzheimer's blood test for symptomatic patients as young as 40 NeurologyLive's clearance report.
PrecivityAD2 is a blood test that helps identify amyloid pathology. That term means the amyloid protein buildup in the brain linked to Alzheimer's disease. Memory clinic patients still need specialist evaluation, should expect to pay out of pocket, and should plan follow-up to interpret the result.
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 Neurologylive — Use this primary source to verify the official guidance.
- Check eligibility on Longevitybenchmark’s official study page — Use this page to check the study’s participation requirements.
Table of Contents
- Who can use this test?
- What does the test measure?
- How accurate are the results?
- How do you get it and what does it cost?
- What should you ask at the memory clinic?
Who can use this test?
The cleared use is narrow. It is for adults 40 and older who already have signs of cognitive impairment. It is not for people without symptoms who want routine screening.
C2N limits the test to use with clinical assessment by professionals experienced in cognitive-impairment evaluation, according to Longevity Benchmark's summary of the company announcement Longevity Benchmark's summary of the C2N announcement. The test aids amyloid-pathology identification. It is not a stand-alone diagnosis.
What does the test measure?
The test uses high-resolution mass spectrometry on a blood sample, according to NeurologyLive. It measures the plasma A-beta 42/40 ratio and percent p-tau217. A-beta refers to amyloid fragments in blood. P-tau217 refers to a phosphorylated form of tau, another Alzheimer's-related protein.
Those two measures are combined into an Amyloid Probability Score 2. The score is reported as negative, positive, or intermediate likely positive. A negative score points away from brain amyloid. A positive score points toward it.
How accurate are the results?
NeurologyLive reports validation in 1,142 symptomatic people checked against amyloid PET scans or spinal-fluid tests. The test showed 97.6% positive predictive value and 93.1% negative predictive value. Positive predictive value means the share of positive results that match amyloid on the reference test.
About 17.3% of people scored likely positive, with 77.3% positive predictive value in that group. That middle group carries more uncertainty. It often calls for clinical judgment and added testing.
How do you get it and what does it cost?
C2N said the FDA-cleared version would become available later in 2026. Its existing CLIA laboratory version remained available to doctors and researchers in the meantime. Patients generally access testing through a clinician, not directly.
C2N's Precivity FAQ states the tests are not currently covered by private payers, Medicare or Medicaid generally, with case-by-case payment possible. Clinicians report a $1,450 list price with a sliding scale down to about $50, according to Neurology Today Neurology Today's report on who pays for blood biomarker tests. Ask the clinic for the current cash price and financial-assistance rules before blood is drawn.
What should you ask at the memory clinic?
Follow-up still matters because no blood test settles the diagnosis alone. According to Being Patient, false positives can prompt a wrong diagnosis and unneeded treatment, false negatives can delay care, and intermediate results often need confirmatory PET or spinal-fluid testing Being Patient's guide to blood-based biomarkers. Bring a list of symptoms, onset dates, medications, and a family member who knows your daily function.
- Is my memory concern the type this test is cleared to evaluate?
- Will a positive, negative, or intermediate result change my next step?
- Do I need PET or spinal-fluid testing to confirm this result?
- What other causes of memory change should we rule out first?
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