Prolia is covered under Medicare Part B, not Part D
Prolia (denosumab) is a prescription injection for osteoporosis that Medicare covers as a Part B drug. This means Medicare pays for the drug itself through Part B, and you typically pay a copay or coinsurance at the time you receive the injection at your doctor's office or infusion center. Part D covers oral medications you pick up at a pharmacy, so Prolia does not fall under that category.
Because Prolia is administered by a healthcare provider rather than self-injected at home, Medicare treats it the same way it treats other injectable drugs given in a medical setting — like chemotherapy or certain biologics. Your doctor's office bills Medicare Part B directly, and you pay your share based on your coverage plan.
Key Takeaways
- Prolia is covered under Medicare Part B because it is given as an injection in a medical office, not taken at home like a pill.
- You pay a copay or coinsurance for each Prolia injection, with the exact amount depending on your specific Medicare plan.
- Your doctor's office handles the Medicare billing, so you do not need to submit a claim yourself.
- Some Medicare Advantage plans may have different coverage rules or require prior authorization before your first dose.
How Medicare Part B covers Prolia
When your doctor prescribes Prolia for osteoporosis, the injection is given in the office during an appointment. The medical staff administers the drug, and your doctor's billing department submits the claim to Medicare Part B. Medicare pays its share (usually 80 percent after you meet your Part B deductible), and you are responsible for the remaining 20 percent coinsurance.
The exact copay or coinsurance amount depends on whether you have Original Medicare with a Medigap supplement, or a Medicare Advantage plan. If you have Original Medicare alone, you will owe 20 percent of the Medicare-approved amount. If you have a Medigap policy, your supplement may cover some or all of that 20 percent. If you have a Medicare Advantage plan, your copay is set by your plan and may be different.
Prolia is given as an injection once every six months, so you will have two appointments per year where this cost applies. Before your first dose, ask your doctor's office what your out-of-pocket cost will be based on your specific Medicare coverage.
What you need to know about prior authorization
Some Medicare Advantage plans require prior authorization before covering Prolia. This means your doctor must contact the plan and get written approval before you receive the first injection. If your plan requires this step and your doctor does not complete it, you may end up paying the full cost of the drug out of pocket.
Ask your Medicare Advantage plan directly whether Prolia requires prior authorization. You can find this information in your plan's formulary (the list of covered drugs) or by calling the customer service number on your insurance card. If prior authorization is needed, your doctor's office can usually handle the request, but it is worth confirming they will do so before your appointment.
Original Medicare does not require prior authorization for Prolia, so if you have Original Medicare with a Medigap supplement, you can proceed with the injection without this extra step.
Comparing your costs across different Medicare plans
Your out-of-pocket cost for Prolia varies depending on which Medicare plan you have. The table below shows how costs typically differ:
| Medicare Plan Type | Your Cost Per Injection | Prior Authorization Required |
|---|---|---|
| Original Medicare (no supplement) | 20% coinsurance of approved amount | No |
| Original Medicare + Medigap | Depends on Medigap plan; may be $0 | No |
| Medicare Advantage | Plan-specific copay (typically $0–$100) | Often yes; check your plan |
The Medicare-approved amount for Prolia changes each year, so your 20 percent coinsurance under Original Medicare will also change. Call your plan or check your plan documents if you want to know the exact dollar amount you will owe for your next injection.
What happens if Prolia is not covered or costs too much
In rare cases, a Medicare plan may not cover Prolia at all, or may cover it only under certain conditions (such as after you have tried another osteoporosis drug first). If your plan denies coverage, your doctor can request an exception or appeal the decision. This process takes time, so ask your doctor to start it as soon as you learn about the denial.
If the cost is more than you can afford, talk to your doctor about other osteoporosis treatments that may be covered at a lower cost. Oral bisphosphonates like alendronate (Fosamax) are often covered under Part D with a lower copay, though they work differently than Prolia and may not be suitable for everyone. Your doctor can help you weigh the options based on your bone health and budget.
You can also contact your state's Health Insurance Counseling and information Program (HICAP) for free help understanding your coverage or appealing a denial. HICAP counselors work with Medicare beneficiaries and can explain your rights.
Questions to ask your doctor before your first Prolia injection
Before you schedule your first appointment, ask your doctor's office these questions so you know what to expect:
- What is my out-of-pocket cost per injection based on my Medicare plan?
- Does my plan require prior authorization, and if so, will your office handle it?
- How often will I need the injection, and for how long?
- What should I do if I cannot afford the copay or coinsurance?
- Are there any other osteoporosis drugs covered at a lower cost under my plan?
Frequently Asked Questions
Can I get Prolia through a mail-order pharmacy instead of at my doctor's office?
No. Prolia must be injected by a healthcare provider, so it cannot be mailed to you or self-injected at home like some other drugs. It is always given in a medical setting, which is why Medicare covers it under Part B rather than Part D.
Will my Medicare Advantage plan cover Prolia if I switch plans during open enrollment?
Most Medicare Advantage plans cover Prolia, but coverage details and copays vary by plan. Before you switch, check the new plan's formulary to confirm Prolia is covered and see what your copay will be. You can compare plans on Medicare.gov during open enrollment.
What if my doctor says I need Prolia but my plan denies it?
Your doctor can file an appeal or request an exception to the denial. Ask your doctor's office to submit this request right away, as the process can take several weeks. You also have the right to appeal the decision yourself by contacting your plan's appeals department.
Does Prolia cost the same at every doctor's office?
Your out-of-pocket cost is the same regardless of which doctor gives you the injection, because Medicare sets the approved amount. However, different offices may bill slightly differently, so it is worth confirming the cost with your specific provider before your appointment.
If I have both Original Medicare and a Medigap plan, do I need to do anything special to use Prolia?
No. Your doctor's office will bill Original Medicare Part B first, and your Medigap plan will automatically cover your coinsurance if your plan includes that benefit. You do not need to submit any paperwork yourself.