Amyloid PET scan with florbetapir (Amyvid)
Measured
A PET scan that shows whether amyloid plaque has built up in the brain. A negative scan means few or no plaques, so Alzheimer's is unlikely to be the cause at that time.
A small amount of a radioactive tracer is injected into a vein. The scan starts 30 to 50 minutes later and takes about 10 minutes. The radiation dose is about 7 mSv, more if a CT is done with it.
In the study behind its FDA approval, checked against autopsy, it found plaque in 92% of the people who had it and correctly cleared 100% of those who did not.
The 2026 Medicare hospital rate for the scan and the tracer together is about $3,148. Since October 2023, Medicare coverage has been decided by its regional claims contractors, not by one national rule.
Only some centers offer it.
Source: api.fda.gov · 2012
Amyloid PET scan with flutemetamol (Vizamyl)
Measured
A PET scan that shows amyloid plaque in the brain, using a different tracer from Amyvid.
The tracer is injected into a vein and the scan starts 60 to 120 minutes later. The radiation dose is about 5.9 mSv.
In its FDA approval study, checked against autopsy, it found plaque in 93% of the people who had it and correctly cleared 84% of those who did not.
The 2026 Medicare hospital rate for the scan and the tracer together is about $3,267. Since October 2023, Medicare coverage has been decided by its regional claims contractors, not by one national rule.
Only some centers offer it.
Source: api.fda.gov · 2013
Amyloid PET scan with florbetaben (Neuraceq)
Measured
A PET scan that shows amyloid plaque in the brain, using a third approved tracer.
The tracer is injected into a vein and the scan starts 45 to 130 minutes later. The radiation dose is about 5.8 mSv.
In its FDA approval study, checked against autopsy, it found plaque in 96.2% of the people who had it and correctly cleared 80% of those who did not.
The 2026 Medicare hospital rate for the scan and the tracer together is about $2,907. Since October 2023, Medicare coverage has been decided by its regional claims contractors, not by one national rule.
Only some centers offer it.
Source: api.fda.gov · 2014
Amyloid PET in everyday practice: the IDEAS study
Measured
A large US study of what happened after doctors ordered an amyloid PET scan for Medicare patients whose memory problems had an uncertain cause. Among more than 16,000 patients, doctors changed the care plan within 90 days for about 60% of those with MCI and 64% of those with dementia.
Medicare paid for these scans because they were part of an approved study.
The study had no comparison group, and a change in the care plan does not show that patients did better.
Source: doi.org · 2019
Medicare's rules for amyloid PET
From 2013 to 2023, Medicare paid for one amyloid PET scan per person, and only inside approved studies. In October 2023 it ended that national rule, partly because the new anti-amyloid drugs need the scan to choose and monitor patients.
Coverage is now decided by Medicare's regional claims contractors, which may cover more than one scan in a person's lifetime.
Source: cms.gov · 2023
How hospitals are paid for scan tracers
Since January 2025, Medicare pays hospitals separately for expensive scan tracers. Before that, the tracer's cost was folded into the payment for the scan, which often did not cover it.
In 2026 the separate tracer payments for the three amyloid tracers are about $1,585 to $1,944. A payment rate does not by itself mean Medicare will cover the scan.
Source: cms.gov · 2025
FDG-PET brain scan
Modelled estimate
A PET scan that shows how actively each part of the brain uses sugar. Alzheimer's and frontotemporal dementia tend to dim different areas, so the scan helps tell them apart.
A radioactive sugar tracer is injected into a vein before the scan, so it involves some radiation.
In a study of 138 people whose diagnosis was later confirmed at autopsy, it identified Alzheimer's in 94% of those who had it and correctly cleared 73% of those who did not.
The 2026 Medicare hospital rate is about $1,461. Medicare covers it to tell Alzheimer's apart from frontotemporal dementia, in people recently diagnosed with dementia who meet the criteria for both.
It is widely available.
Source: doi.org · 2001
FDG-PET to predict whether MCI will progress
Modelled estimate
The same sugar-uptake scan, used in people with mild cognitive impairment (MCI) to estimate who will go on to develop Alzheimer's dementia.
A Cochrane review of 14 studies estimated that it picks up 76% of the people who progress, at a setting that correctly clears 82% of those who do not. Results varied widely from study to study.
Medicare does not cover it for this purpose except within approved clinical trials.
The reviewers found the evidence too variable to support routine use in MCI.
Source: doi.org · 2015
Brain MRI
A scan that shows the brain's structure: shrinkage, damage to the white matter, past strokes, bleeds, tumors and fluid build-up. It is usually the first scan in a memory workup.
It uses magnets and radio waves, not radiation. Contrast dye is sometimes added.
The 2026 Medicare hospital rate is about $244 without contrast. Medicare covers it when it is medically necessary.
It is widely available.
Source: pmc.ncbi.nlm.nih.gov · 2025
Head CT scan
An X-ray scan of the head that shows large problems such as bleeding, tumors, fluid build-up, large strokes or marked shrinkage.
It uses X-rays, so there is some radiation.
The 2026 Medicare hospital rate is about $107. Medicare covers it when it is medically necessary.
It is used instead of MRI when MRI is not available or not safe for the person.
Source: pmc.ncbi.nlm.nih.gov · 2025
Cognivue computer screening test
Measured
A test the person takes alone on a computer. It screens thinking skills in adults 55 and older and flags those who should have further testing. It is a screening aid, not a diagnosis. The FDA authorized it in 2015.
The result is produced automatically at the end of the test.
Compared with a paper screening test (SLUMS), it flagged 64% of the people that test rated as impaired and cleared 92% of the rest.
Medicare has no separate payment for the device itself. Tests like it are usually billed as a short computer-scored test, at about $30 at the 2026 Medicare hospital rate.
Source: api.fda.gov · 2015
CANTAB Mobile memory test
Measured
A touchscreen memory test in which the person remembers where patterns were hidden. The FDA cleared it in 2017 as a screening aid.
The result is produced automatically at the end of the test.
In one study of 65 people, compared with the MoCA test, it flagged 77% of those with MCI and cleared 74% of the rest. The study was very small.
Medicare has no separate payment for the device itself. Tests like it are usually billed as a short computer-scored test, at about $30 at the 2026 Medicare hospital rate.
Only some clinics offer it.
Source: api.fda.gov · 2017
BrainCheck cognitive test
Measured
A set of memory, attention and visual-spatial tasks on a tablet or computer, scored against people of the same age. A search of the FDA's clearance database found no clearance for it.
The result is produced automatically at the end of the test.
In one study it identified 81% of people with impairment and cleared 94% of those without, although only 18 of them had a doctor's diagnosis to check against.
Medicare has no separate payment for the device itself. Tests like it are usually billed as a short computer-scored test, at about $30 at the 2026 Medicare hospital rate.
Only some clinics offer it.
Source: doi.org · 2019
Digital clock-drawing test (DCTclock)
Modelled estimate
The person draws a clock on a tablet, and software scores how they draw it, not only the finished picture. A search of the FDA's clearance database found no clearance for it.
Pooled across 17 digital clock tests, not this one alone, the tests flagged about 76.5% of people with MCI and cleared about 75.2% of those without.
Medicare has no separate payment for the device itself. Tests like it are usually billed as a short computer-scored test, at about $30 at the 2026 Medicare hospital rate.
Only some clinics offer it.
Source: doi.org · 2026
Medicare cognitive assessment and care-planning visit
Measured
A visit of about an hour in which a clinician assesses thinking and daily function and writes a care plan. Office memory tests, including digital ones, are paid for through this visit or as a short computer-scored test.
Medicare Part B covers it. In 2024 Medicare paid an average of about $256 for the visit in a doctor's office.
Source: data.cms.gov · 2024
Amyloid and tau PET together, in people without symptoms
Measured
A study of 1,325 people with normal thinking who had both an amyloid PET and a tau PET scan, followed to see who developed MCI. Those with amyloid and with tau in the outer temporal lobe were about 19 times as likely to develop MCI as those with neither.
These were research volunteers, and the groups with both proteins were small, so the estimates are wide. Only some centers offer it.
Source: doi.org · 2022
What an abnormal amyloid or tau result means
Modelled estimate
A review that pooled 36 studies, 7,793 people in all, to estimate how much an abnormal amyloid or tau result raises the chance of getting worse. People with MCI and abnormal amyloid had about 5 times the odds of developing dementia; with abnormal amyloid and tau together, about 12 times. PET scans and spinal fluid tests gave consistent results.
Source: doi.org · 2024
Amyloid PET to predict whether MCI will progress
Measured
A Cochrane review of whether a florbetapir scan can show which people with MCI will develop Alzheimer's dementia.
In the largest study, of 401 people followed for 1 to 2 years, it picked up 89% of those who progressed but correctly cleared only 58% of those who did not.
The reviewers concluded it should not be used routinely for this purpose.
Source: doi.org · 2017
MRI measurement of cortical thinning
Measured
A way of measuring the thickness of the brain areas Alzheimer's affects first. In two small groups of healthy adults, those who developed Alzheimer's dementia 7 to 11 years later already had a thinner cortex, by about 0.2 mm.
Only 15 people in the study developed dementia, so the estimates are imprecise. It is used in research, not in routine care.
Source: doi.org · 2011
7 Tesla MRI
Very high-strength MRI that shows fine structure, such as parts of the hippocampus and tiny bleeds, that standard scanners cannot. A review found 19 studies, most of them in Alzheimer's.
The studies were small and did not follow people over time. It is used in research, not in routine care.
Source: doi.org · 2017
Diffusion MRI of the white matter
Modelled estimate
An MRI method that shows damage to the brain's wiring that a standard MRI does not. A review of 41 studies found changes in most white-matter regions in Alzheimer's and in MCI.
There are no cut-offs for using it to diagnose anyone. It is used in research, not in routine care.
Source: doi.org · 2011
Resting-state functional MRI
Modelled estimate
An MRI that shows how brain networks work together while the person rests. A review of 34 studies found consistent changes in three networks in Alzheimer's and MCI.
It has no established use in diagnosis, and the studies were small, about 40 people each. It is used in research, not in routine care.
Source: doi.org · 2017
Blood-flow MRI (arterial spin labeling)
Modelled estimate
An MRI method that measures blood flow in the brain without radiation or dye. It has been proposed as an alternative to FDG-PET.
Pooled across 10 studies, it identified 83% of people with Alzheimer's and cleared 81% of healthy people.
The studies were of low quality and compared people with Alzheimer's only with healthy people, not with other dementias, which makes the test look more accurate than it would be in a clinic. It is used in research, not in routine care.
Source: doi.org · 2024
MRI checks during anti-amyloid treatment
People on lecanemab need brain MRIs to watch for swelling and small bleeds (ARIA): one before starting, and more before the 5th, 7th and 14th infusions. In the main lecanemab trial, ARIA showed on MRI in 12.6% of participants, and 2.8% had symptoms.
Each scan is about $244 at the 2026 Medicare hospital rate, and the first year needs 4 or 5 scans. Medicare covers brain MRI as a standard service.
Source: doi.org · 2023