Alzheimer’s blood tests are now available through major commercial labs in the United States, including Labcorp and Quest Diagnostics. The first FDA-cleared blood test for diagnosing Alzheimer’s disease received approval in May 2025, and several other lab-developed tests have been available even longer. Most require a doctor’s order, meaning your first step is a conversation with your primary care physician or a neurologist, who can then send you to a nearby lab for a standard blood draw.
Which Tests Are Available Right Now
The FDA-cleared test is called Lumipulse, made by Fujirebio Diagnostics. It measures a ratio of two proteins in your blood: a specific form of phosphorylated tau (p-tau217) and a fragment of amyloid-beta. Both of these proteins are linked to the amyloid plaques that build up in the brains of people with Alzheimer’s. The test is cleared for adults aged 55 and older who are already showing signs of cognitive problems.
Beyond Lumipulse, the two largest commercial lab networks offer their own panels. Labcorp provides tests for p-tau217, p-tau181, the amyloid-beta 42/40 ratio, and two additional markers that reflect nerve cell damage and brain inflammation. Quest Diagnostics offers a test called AD-Detect, which measures p-tau181. These lab-developed tests don’t carry the same FDA clearance as Lumipulse but are run under standard clinical laboratory regulations.
How to Get One
You typically need a physician’s order. Start with your primary care doctor or a neurologist. If they agree testing is appropriate, they’ll write an order and you’ll go to a Labcorp or Quest patient service center for a blood draw, the same way you’d get cholesterol or blood sugar checked. Some specialty memory clinics and academic medical centers also offer these tests as part of their diagnostic workup.
These tests are not currently available as direct-to-consumer kits. You won’t find them at a pharmacy or through an at-home testing service. The reason is partly practical: results need clinical context to interpret correctly, and a positive result doesn’t confirm an Alzheimer’s diagnosis on its own.
How Accurate These Tests Are
The p-tau217 blood test is the standout performer. In clinical studies, it detected amyloid buildup in the brain with 90 to 95% accuracy, making it remarkably close to the gold-standard methods that previously required either a spinal tap or a PET brain scan costing thousands of dollars. In one head-to-head comparison published in the journal Neurology, p-tau217 blood testing achieved 97% sensitivity for identifying Alzheimer’s pathology confirmed by spinal fluid analysis, meaning it caught nearly every true case. Its specificity was 70%, meaning about 3 in 10 people without Alzheimer’s pathology received a falsely positive result.
The older p-tau181 tests are somewhat less precise, with accuracy around 80%. The amyloid-beta 42/40 blood ratio also lands around 80% accuracy. These numbers are good enough to be clinically useful as a screening step but not as definitive as p-tau217.
For comparison, the p-tau217 blood test actually outperformed a type of brain PET scan (FDG-PET) that has been used for years. The blood test had an overall accuracy of 84% versus 72% for the PET scan in distinguishing Alzheimer’s from other causes of dementia. That’s a significant shift in how doctors can approach diagnosis.
What the Results Tell You
A blood test result is not a yes-or-no Alzheimer’s diagnosis. It tells your doctor the likelihood that amyloid plaques are present in your brain. Think of it as a probability score that gets combined with your symptoms, cognitive testing, medical history, and sometimes additional imaging. A negative result is especially useful because it makes Alzheimer’s much less likely and can steer your doctor toward investigating other causes of memory problems, like thyroid issues, vitamin deficiencies, depression, or other types of dementia.
A positive result means further evaluation is warranted. Your doctor may recommend a PET scan or additional cognitive testing to confirm the diagnosis. This layered approach is important because some results fall into an intermediate zone where the proteins are mildly elevated but not clearly in the Alzheimer’s range.
Who Should Consider Getting Tested
The FDA-cleared Lumipulse test is specifically intended for people aged 55 and older who are already experiencing cognitive symptoms, such as noticeable memory loss, difficulty with planning or problem-solving, or confusion with time and place. It’s designed to help doctors determine whether those symptoms are caused by Alzheimer’s rather than something else.
These tests are not currently recommended for people with no symptoms who simply want to know their future risk. The Alzheimer’s Association’s 2025 clinical practice guideline positions blood biomarker testing within specialized care settings, as a tool to help clinicians either triage patients who need further workup or confirm suspected Alzheimer’s pathology. If you’re experiencing cognitive changes that concern you, that’s the right time to bring it up with your doctor.
Cost and Insurance Coverage
Pricing varies depending on the specific test and your insurance. Lab-developed tests from Labcorp and Quest can range from roughly $200 to $500 or more without insurance. Medicare coverage for Alzheimer’s blood tests specifically is still evolving. Medicare Part B covers certain diagnostics and treatments related to Alzheimer’s, including scans and monoclonal antibody therapies like lecanemab, but coverage decisions for newer blood biomarker tests may depend on how your provider codes the order and whether the test has FDA clearance.
The FDA clearance of Lumipulse is expected to accelerate insurance coverage decisions, since insurers are more likely to reimburse tests with formal regulatory backing. In the meantime, ask your doctor’s office to check with your insurer before ordering, and ask the lab directly about out-of-pocket costs if you’re paying on your own.
Why This Matters Now
Until recently, confirming Alzheimer’s pathology required either a lumbar puncture to analyze spinal fluid or an amyloid PET scan that can cost $5,000 or more and isn’t widely available outside major medical centers. A simple blood draw at a local lab changes the accessibility equation dramatically. It also matters because new Alzheimer’s treatments that clear amyloid from the brain are now on the market, and those drugs require confirmation of amyloid pathology before treatment can begin. Blood tests make that confirmation faster, cheaper, and far less invasive, opening a path to earlier treatment for more people.