Does Medicare Cover DaTscan: Part B Rules, Costs, and Authorization

Medicare does cover DaTscan in most cases. The test is paid under Medicare Part B as a diagnostic imaging service when a physician orders it to help resolve an unclear diagnosis, and you pay the usual Part B cost-sharing after your deductible. There is no national Medicare rule dedicated to the scan, so the specific criteria are set by regional Medicare contractors and, for Medicare Advantage enrollees, by the plan itself.¹²

When Part B Pays for the Scan

Part B covers diagnostic non-laboratory tests, including nuclear medicine scans, when a physician orders them to diagnose or rule out a condition.³ DaTscan fits that definition, and in practice it is routinely reimbursed when the medical necessity criteria are met.²

CMS has not issued a national coverage determination specific to DaTscan, so local Medicare administrative contractors decide the details in their regions.¹ That means the criteria your doctor has to document can look slightly different depending on where you live, even though the underlying standard is similar.

One rule is uniform: if the scan is performed outside a hospital, the imaging facility must hold the required accreditation for nuclear medicine. Medicare will not pay for a scan done at an unaccredited non-hospital facility, and the facility is not allowed to bill you for it either.³

What Counts as Medical Necessity

The scan is considered medically necessary in two main situations: clinically uncertain Parkinson’s disease and clinically uncertain dementia with Lewy bodies.¹ “Clinically uncertain” means the diagnosis is still unclear after a full neurological exam, medical history, and review of symptom duration and progression.

The most common reason for ordering the scan is to separate essential tremor from a parkinsonian syndrome. Essential tremor does not involve dopamine loss, so those scans look normal, while Parkinson’s disease, multiple system atrophy, and progressive supranuclear palsy typically show reduced uptake.⁴ The record must show that the clinical evaluation was inconclusive and that the results are expected to change the treatment plan.

Some Medicare Advantage policies spell out the covered indications more specifically. Blue Cross Blue Shield of Michigan’s Medicare Advantage policy, for example, covers the scan when a board-certified neurologist who has personally evaluated the patient orders it to differentiate essential tremor from Parkinson’s disease, distinguish drug-induced parkinsonism from degenerative parkinsonism, plan for deep brain stimulation surgery, or differentiate Lewy body dementia from Alzheimer’s disease.⁵

Situations Medicare Will Not Cover

Coverage has real limits. A DaTscan is generally not covered as a screening test, as a confirmatory test when the clinical diagnosis is already clear, for monitoring disease progression or treatment response, or for serial repeat scans. Its use for diagnosing or managing Alzheimer’s disease, as opposed to Lewy body dementia, is considered investigational by most payers.⁶

Most people diagnosed with Parkinson’s disease do not need the scan at all. When a patient has classic motor symptoms and responds to levodopa, the clinical diagnosis is usually enough on its own. The scan adds value in ambiguous cases, not routine ones.²

What You Will Pay Out of Pocket

A DaTscan has two billable pieces: the radiopharmaceutical tracer and the imaging procedure. The tracer, ioflupane I-123, is billed under HCPCS code A9584, with a Medicare-allowed amount of roughly $2,955 in 2026.⁷ The SPECT imaging is typically billed under CPT code 78803.⁸ When the scan is done in a hospital outpatient department, the tracer’s cost is packaged into the facility’s overall payment rather than paid as a separate line item.⁹

Once you meet your annual Part B deductible, Medicare pays 80% of the approved amount and you owe the remaining 20% as coinsurance. In a hospital outpatient setting, your share may take the form of a fixed copayment rather than a flat 20%.

Assignment matters. When a provider accepts Medicare assignment, they take the Medicare-approved rate as full payment, and your responsibility is capped at the standard coinsurance. Providers who do not accept assignment can charge up to 115% of the approved amount, and you pay the difference.¹⁰ If you carry Medigap or Medicaid, some or all of the coinsurance may be picked up depending on your plan.

Medicare Advantage and Prior Authorization

Medicare Advantage (Part C) plans generally cover DaTscan, but the criteria and paperwork vary. Under 42 CFR § 422.101, when CMS has not fully developed coverage rules for a service, Medicare Advantage plans can apply their own medical policies.⁵

Advanced imaging often triggers prior authorization on Medicare Advantage. A January 2024 CMS final rule requires those plans to give specific reasons for any denials and to meet shortened decision timeframes.¹¹ Call your plan before you schedule the scan so preapproval, if needed, is in hand.

Steps to Confirm Coverage Before You Go

Call your plan. Ask specifically whether HCPCS code A9584 and CPT code 78803 are covered under your benefit, and get the answer in writing when you can.
Ask about prior authorization. Find out what documentation your neurologist needs to submit and how long approval takes.
Confirm the facility’s accreditation for nuclear medicine if the scan will be done outside a hospital. Medicare will not pay for scans at unaccredited non-hospital facilities.³
Ask whether the facility accepts Medicare assignment. If it does, your out-of-pocket cost is limited to the standard 20% coinsurance after the deductible.
Check any supplemental coverage. Medigap or Medicaid may cover the Part B coinsurance for diagnostic imaging.

1
Premera Blue Cross. Dopamine Transporter Imaging With Single-Photon Emission Computed Tomography
2
The Michael J. Fox Foundation. Ask MD: DaTscan and Parkinsons
3
Medicare.gov. Diagnostic Non-Laboratory Tests
4
Blue Cross Blue Shield of Florida. DaTscan Medical Coverage Guideline
5
Blue Cross Blue Shield of Michigan. Dopamine Transporter Imaging With SPECT
6
Blue Cross Blue Shield of Mississippi. Dopamine Transporter Imaging With Single-Photon Emission Computed Tomography
7
Noridian Healthcare Solutions. Radiopharmaceutical Fees
8
GE HealthCare. DaTscan Reimbursement Cards
9
Society of Nuclear Medicine and Molecular Imaging. HOPPS Payment Rates
10
Center for Medicare Advocacy. Medicare Part B
11
American Academy of Family Physicians. Prior Authorization