A Dual-Energy X-ray Absorptiometry (DEXA) scan is a non-invasive imaging procedure that uses low-dose X-rays to measure bone mineral density, typically in the hip and spine. The primary purpose of this quick, painless test is to diagnose or monitor osteoporosis, a condition characterized by weakened and brittle bones. Since bone mass measurement is a standard part of managing bone health, understanding Medicare coverage for this service is important.
Coverage Details Under Medicare Part B
Medicare provides coverage for bone mass measurements primarily under Medicare Part B, which is Medical Insurance. Part B covers outpatient medical services, including certain preventive services and diagnostic tests ordered by a healthcare provider. A DEXA scan is covered when a physician orders it to determine the presence or extent of osteoporosis or to monitor treatment effectiveness. When eligibility criteria are met, the test must be performed by a facility that accepts Medicare assignment and is considered a preventive service, often resulting in no out-of-pocket costs.
Eligibility Requirements and Testing Frequency
Qualifying Conditions
Medicare has specific requirements to qualify for a covered bone mass measurement. Coverage is granted to individuals who meet one of the following criteria:
- Having an estrogen deficiency and being at clinical risk for osteoporosis.
- Having X-rays that show vertebral abnormalities suggesting osteoporosis or osteopenia.
- Being diagnosed with primary hyperparathyroidism.
- Receiving long-term glucocorticoid therapy, such as prednisone.
- Being monitored to assess the response to FDA-approved osteoporosis drug therapies.
Testing Frequency
For most eligible beneficiaries, the covered frequency is strictly limited to one bone mass measurement every 24 months. If a healthcare provider determines that a patient’s medical condition requires more frequent testing, the scan may be covered more often, but this requires specific medical justification.
Beneficiary Costs for a DEXA Scan
When a DEXA scan is covered as a preventive service and eligibility criteria are met, the financial responsibility is minimal. Under Original Medicare Part B, beneficiaries typically pay zero coinsurance, and the Part B deductible does not apply. This zero-cost structure requires the provider to accept Medicare assignment. If the scan does not meet preventive criteria or exceeds the two-year limit without medical necessity, it is reclassified as a diagnostic service. Standard Part B cost-sharing rules apply, requiring the beneficiary to pay the deductible (if unmet) and 20% of the Medicare-approved amount.
How Medicare Advantage and Supplement Plans Affect Coverage
Medicare Advantage (Part C)
Medicare Advantage (Part C) plans must cover the DEXA scan when it meets Original Medicare’s eligibility and frequency rules. While the coverage is equivalent, the specific cost-sharing structure may differ from Part B’s zero-cost provision. Part C plans often use copayments instead of coinsurance, and the amount varies based on the plan and network status. Beneficiaries must also adhere to any network restrictions the plan enforces, such as needing prior authorization or using specific imaging centers.
Medicare Supplement (Medigap)
Medicare Supplement Insurance (Medigap) plans are designed to cover the out-of-pocket costs associated with Original Medicare. If a DEXA scan is covered but the patient is responsible for the 20% coinsurance because the service is diagnostic, a Medigap policy would typically cover that cost-sharing amount. The specific Medigap plan letter determines exactly which costs are covered.