Medicare covers a bone density test once every 24 months for beneficiaries who qualify. In some cases, Medicare will pay for testing more frequently if your doctor determines it is medically necessary.
The Standard 24-Month Rule
Under Medicare Part B, you can receive a bone mass measurement once every two years (24 months). This is the baseline schedule for most people who meet Medicare’s eligibility criteria. The 24-month clock starts from the date of your last Medicare-covered bone density test, not from the calendar year. So if you had a scan in March 2024, your next covered scan would be available starting in March 2026.
Who Qualifies for Coverage
Medicare doesn’t cover bone density testing for everyone automatically. You need to fall into one of several qualifying categories. These generally include:
- Estrogen-deficient women at risk for osteoporosis, based on their medical history and other risk factors
- People with vertebral abnormalities, such as fractures or bone loss visible on an X-ray
- People taking or planning to take long-term steroid medications (like prednisone), which are well known to weaken bones over time
- People with primary hyperparathyroidism, a condition where overactive parathyroid glands cause calcium to leach from bones
- People being monitored for an approved osteoporosis drug treatment, where the scan helps determine whether the medication is working
Your doctor needs to order the test, and the order should document which qualifying condition applies to you. Without a qualifying condition on file, Medicare may deny the claim.
When Medicare Covers Tests More Often
The “more often if medically necessary” exception is important and comes up in several real-world situations. If your doctor can document a clinical reason for testing sooner than 24 months, Medicare may approve coverage on a shorter timeline.
Common scenarios where more frequent testing gets approved include starting a new osteoporosis medication where your doctor wants to check your response sooner, discovering a new fracture that suggests rapid bone loss, or beginning a course of high-dose corticosteroids that can damage bone quickly. In each case, your doctor makes the medical necessity argument to Medicare, and the documentation matters. If your provider doesn’t clearly explain why earlier testing is needed, the claim could be denied even if the reason is legitimate.
What You Pay Out of Pocket
Bone density testing falls under Medicare Part B. Once you’ve met your annual Part B deductible, you typically pay 20% of the Medicare-approved amount for the test. The facility or provider bills Medicare directly for the remaining 80%. If you have a Medigap (supplemental) policy, it may cover part or all of your 20% coinsurance, depending on your plan.
If you have a Medicare Advantage plan instead of Original Medicare, your plan is required to cover bone density testing at least as often as Original Medicare does. However, your cost-sharing (copays or coinsurance) may differ, so check with your specific plan for the exact amount you’ll owe.
What the Test Involves
The most common type of bone density test is a DXA scan (sometimes written as DEXA). It uses a very low dose of radiation to measure bone mineral density, usually at the hip and spine. The scan itself takes about 10 to 15 minutes, is completely painless, and requires no preparation. You lie on a padded table while a scanning arm passes over your body.
Peripheral bone density tests, which measure density at the wrist, heel, or finger, also exist and are sometimes used as screening tools. These are quicker and use smaller, portable machines, but a central DXA scan of the hip and spine is considered the gold standard for diagnosing osteoporosis and tracking changes over time. If your doctor orders a peripheral test, confirm that it will be covered under your specific situation before the appointment.
How to Avoid Surprise Denials
The most common reason for a denied bone density claim is timing. If you schedule a scan before the full 24 months have passed from your last covered test, Medicare will reject it unless your doctor has documented medical necessity for earlier testing. Before booking your appointment, check the date of your last scan and count forward 24 months.
Another common issue is missing documentation. Your doctor’s order should specify which qualifying condition applies to you. If you’re unsure whether you meet the criteria, ask your doctor’s office directly. They handle these claims regularly and can tell you whether your situation qualifies. If your claim is denied, you have the right to appeal, and your doctor’s office can help you through that process by providing the supporting medical records Medicare needs to reconsider.