The third FDA-cleared Alzheimer's blood-biomarker test is C2N Diagnostics' PrecivityAD2, cleared August 20, 2026 for symptomatic adults 40 and older in the company announcement. This blood test measures amyloid-linked proteins, and UCHealth Today reports a $1,450 list cost in its cost report, with confirmation steps to discuss.
Amyloid pathology means a buildup of Alzheimer's-linked proteins in the brain. AJMC reports PrecivityAD2 is meant to flag that pathology alongside clinical assessment by experienced professionals, not as a standalone test. AJMC also reports a single blood draw offers a less invasive option than spinal-fluid or PET testing and may support earlier treatment decisions.
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 C2N — Use this primary source to verify the official guidance.
- Check eligibility on Mlo Online’s official study page — Use this page to check the study’s participation requirements.
Table of Contents
- Who should consider testing?
- How does PrecivityAD2 work?
- What will it cost and how do you get it?
- What should you ask after a result?
Who should consider testing?
AJMC reports the test is for adults 40 and older with signs or symptoms of cognitive impairment who are undergoing evaluation. A professional experienced in cognitive impairment uses the result with clinical assessment to identify amyloid pathology. It is not intended as standalone screening. Being Patient notes blood-biomarker results alone cannot definitively diagnose Alzheimer's disease.
False positives are much higher in people without cognitive symptoms. Guidance therefore recommends testing only after clinical evaluation for memory impairment. Start with a primary-care or memory-clinic visit that documents new symptoms. Ask whether referral to an experienced evaluator is needed before any blood test. Bring examples of changes in memory, language, or daily tasks.
How does PrecivityAD2 work?
NeurologyLive reports PrecivityAD2 uses high-resolution mass spectrometry, a lab method that measures proteins precisely, to measure plasma Aβ42/40 and percent p-tau217. Aβ42/40 is the ratio of two amyloid fragments in blood, while percent p-tau217 reflects a tau form linked to Alzheimer's. The two measures combine into an Amyloid Probability Score 2 reported as negative, positive, or likely positive. In 1,142 symptomatic adults compared with amyloid PET or spinal-fluid testing, NeurologyLive reports 97.6% positive predictive value and 93.1% negative predictive value in its accuracy summary.
About 17.3% of people had likely-positive results, with 77.3% positive predictive value. A likely-positive result signals higher risk but less certainty than a clear positive. A clear positive means the blood result matched amyloid on PET or spinal-fluid testing most of the time. A clear negative means the blood result matched the absence of amyloid most of the time. A likely-positive result most often leads to discussion of added confirmation.
What will it cost and how do you get it?
UCHealth Today notes the $1,450 figure describes the C2N-laboratory version and that coverage is generally limited. The maker offers patient assistance for qualifying patients. Ask the ordering clinic what the current charge includes and whether assistance applies. AJMC reports the test is used with clinical assessment by professionals experienced in cognitive impairment.
A single blood draw is less invasive than spinal-fluid testing or amyloid PET. Ask whether your clinic evaluates cognitive symptoms itself or refers to a memory specialist. Call your insurer before the visit with the test name and lab. Ask about prior authorization, out-of-pocket cost, and assistance forms. Write down the answers to compare with the clinic's estimate.
What should you ask after a result?
Alzheimer's Association guidance distinguishes triage use from confirmatory use by accuracy thresholds, as summarized by MLO Online in the guidance summary. Triage means an initial sort that may need more testing. Confirmatory means the result alone can support a pathology decision. MLO Online notes patients with new symptoms should ask whether a positive or likely-positive result needs PET or spinal-fluid confirmation.
They should also ask how the result affects diagnosis, treatment eligibility, care planning, or trial referral. These four topics shape next steps more than the score alone. Bring a one-page timeline of symptoms, medications, and prior tests to that follow-up visit. Ask who will explain the result and when. Leave with a written plan for confirmation, diagnosis, and next appointments.
- Does my positive or likely-positive result need PET or spinal-fluid confirmation?
- How does this result change my diagnosis?
- Does it affect treatment eligibility?
- What should we plan for care and support?
- Should I consider trial referral?
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