Medicare Part B provides essential medical insurance for outpatient services, doctor visits, preventive care, and certain medical supplies. Many people assume it also covers everyday prescription medications they take at home. This assumption is common but incorrect.
Part B has very narrow coverage for prescription drugs, limited to those administered by a healthcare professional in specific settings. Most oral medications, pills, or self-injected drugs taken at home fall outside Part B benefits. This distinction confuses many beneficiaries who expect broader drug coverage.
Separate Medicare Part D (prescription drug coverage) or Medicare Advantage plans with drug benefits fill the gap for routine prescriptions. Understanding what Part B actually covers for drugs helps people avoid surprises and choose the right coverage combination.
What Medicare Part B Covers for Prescription Drugs
Medicare Part B covers limited prescription drugs when a healthcare professional administers them in an approved setting. This includes drugs given in a doctor’s office, outpatient hospital department, or clinic. Coverage applies to injectable or infused medications that require professional supervision.
Common examples include chemotherapy drugs, certain injectable osteoporosis treatments, anti-viral drugs for hepatitis, and injectable rheumatoid arthritis medications. Part B also covers some vaccines when administered in a medical setting, such as pneumococcal and hepatitis B vaccines for high-risk individuals.
The key requirement is that the medication must be provided incident to a physician’s service. Self-administered drugs taken at home, even if prescribed by a doctor, do not qualify under Part B.
Drugs Covered Under Part B (Administered by Professionals)
Part B covers a specific list of medications that healthcare providers administer directly. These include:
- Chemotherapy drugs for cancer treatment
- Injectable drugs for rheumatoid arthritis (such as infliximab or abatacept)
- Certain anti-hemophilic drugs
- Injectable osteoporosis medications (such as denosumab)
- Some immunosuppressive drugs following organ transplant
These drugs are covered at 80% of the Medicare-approved amount after the annual Part B deductible. The patient pays 20% coinsurance on the approved cost. Providers who accept assignment cannot charge more than the approved rate.
Drugs Not Covered Under Part B
Part B excludes most prescription drugs that patients self-administer at home. This includes:
- Oral medications (pills or tablets)
- Self-injected insulin and other diabetes medications
- Inhalers for asthma or COPD
- Topical creams or ointments
- Eye drops
- Most pain medications
These drugs require separate coverage through Medicare Part D (standalone prescription drug plans) or Medicare Advantage plans that include drug coverage (MA-PD). Without Part D or MA-PD, beneficiaries pay 100% of the cost for these medications.
Comparison of Prescription Drug Coverage
Here’s a clear comparison of how prescription drugs are covered under different parts of Medicare:
| Type of Drug / Administration | Part B Coverage | Part D Coverage | Typical Patient Cost (Part B) |
|---|---|---|---|
| Drugs administered by professional in office/clinic | Yes (80% after deductible) | Not covered | 20% coinsurance |
| Self-administered oral medications | No | Yes (if on plan formulary) | 100% out-of-pocket |
| Self-injected insulin & diabetes drugs | No | Yes (with possible special rules) | 100% out-of-pocket |
| Most vaccines (flu, COVID) | Yes (100%, no deductible) | Not covered | $0 |
This table shows the clear division between Part B and Part D coverage.
How Part B Covers Certain Injections and Infusions
Part B covers injectable or infused drugs when a healthcare professional administers them in an approved facility. This includes chemotherapy infusions in outpatient settings, injectable migraine treatments in a doctor’s office, and certain biologic drugs for autoimmune conditions.
Coverage requires that the drug is reasonable and necessary for the patient’s condition. The provider must bill Medicare correctly using appropriate codes. Patients pay 20% coinsurance after the deductible, and the provider accepts assignment to limit extra charges.
Some drugs have special payment rules. For example, certain infused drugs have an additional payment for administration. These details are handled automatically when claims are submitted properly.
Vaccines Covered Under Part B
Medicare Part B covers several preventive vaccines at 100% (no deductible or coinsurance) when administered in-network. These include:
- Pneumococcal vaccines (both PCV13 and PPSV23)
- Hepatitis B vaccine for high-risk individuals
- Influenza (flu) vaccine annually
- COVID-19 vaccines
These vaccines are covered under Part B rather than Part D because they are preventive services. Other vaccines (such as shingles or travel vaccines) fall under Part D and may have copays depending on the plan.
Transition to Part D for Most Home-Use Prescriptions
Most prescription drugs taken at home—oral medications, self-injected insulin, inhalers, eye drops, and topical treatments—require Medicare Part D coverage. Part D plans are offered by private insurers and have their own formularies, premiums, deductibles, and copays.
Without Part D or a Medicare Advantage plan with drug coverage, beneficiaries pay full retail price for these medications. Late enrollment in Part D results in a permanent penalty added to future premiums. Planning ahead prevents this costly gap.
Key Differences Between Part B and Part D Drug Coverage:
- Part B: Focuses on professional-administered drugs and certain vaccines.
- Part D: Covers most self-administered prescriptions taken at home.
- Both parts may be needed for complete medication coverage.
- Coordination between providers and pharmacies prevents coverage gaps.
Medicare Advantage Plans and Drug Coverage
Medicare Advantage (Part C) plans combine Parts A, B, and often D into one plan. Most Advantage plans include prescription drug coverage (MA-PD plans). These plans must cover at least as well as standalone Part D plans.
Some Advantage plans offer $0 premium drug coverage with copays for generics and brand-name medications. Others have lower deductibles or better coverage in the coverage gap. In-network pharmacies provide the lowest costs.
Review the plan’s formulary (list of covered drugs) and pharmacy network before enrolling. Switching plans during open enrollment allows better alignment with current prescriptions.
Conclusion
Medicare Part B covers only a limited set of prescription drugs—those administered by a healthcare professional in an approved setting—and certain preventive vaccines at no cost. Most everyday prescriptions taken at home (oral medications, self-injected insulin, inhalers, etc.) require separate Part D coverage or inclusion in a Medicare Advantage plan. Understanding this clear division helps beneficiaries avoid gaps, choose appropriate plans, and manage medication costs effectively. Combining Part B with Part D or a comprehensive Advantage plan ensures the broadest prescription protection for long-term health needs.
FAQ
Does Medicare Part B cover prescription drugs?
Medicare Part B covers only a limited number of prescription drugs that are administered by a healthcare professional in a doctor’s office, clinic, or outpatient facility. This includes chemotherapy drugs, certain injectable treatments, and specific vaccines. Most oral medications and self-administered drugs are not covered under Part B.
What types of prescription drugs does Part B cover?
Part B covers drugs given by injection or infusion in a medical setting, such as chemotherapy, certain rheumatoid arthritis biologics, anti-hemophilic drugs, and injectable osteoporosis treatments. It also covers preventive vaccines like flu, pneumococcal, and hepatitis B for high-risk individuals. Coverage requires professional administration.
Are oral prescription medications covered under Part B?
No, oral prescription medications (pills, tablets, capsules) are not covered under Part B. These require separate Medicare Part D coverage or inclusion in a Medicare Advantage plan with drug benefits. Beneficiaries pay full cost without Part D.
Does Medicare cover self-injected drugs like insulin under Part B?
No, self-injected drugs such as insulin, epinephrine, or most diabetes injections are not covered under Part B. These fall under Medicare Part D. Certain professional-administered injections (such as in-office treatments) may qualify under Part B.
How does Medicare Advantage handle prescription drug coverage?
Most Medicare Advantage plans include prescription drug coverage (MA-PD plans) and must cover drugs at least as well as standalone Part D plans. They often use fixed copays instead of coinsurance and have in-network pharmacy requirements. Check your plan’s formulary and pharmacy network.
What happens if I have Part B but no Part D coverage?
Without Part D or a Medicare Advantage plan with drug coverage, you pay 100% of the cost for most prescription medications taken at home. This includes oral drugs, self-injected insulin, inhalers, and eye drops. Late enrollment in Part D results in a permanent penalty.
Are vaccines covered under Part B or Part D?
Medicare Part B covers preventive vaccines such as flu, pneumococcal, hepatitis B (for high-risk individuals), and COVID-19 at 100% with no deductible. Other vaccines, such as shingles or travel vaccines, fall under Part D and may have copays depending on the plan.
Does Medicare cover drugs given during a hospital stay?
Drugs administered during a covered inpatient hospital stay are covered under Medicare Part A as part of hospital services. This includes IV medications and injections given in the hospital. Coverage ends upon discharge.
Can I use my Part B coverage for drugs at a clinic?
Yes, Part B covers prescription drugs administered in a doctor’s office, outpatient hospital department, or clinic when professional administration is required. Examples include chemotherapy infusions or certain biologic injections. You pay 20% coinsurance after the deductible.
How do I find out which drugs Part B covers?
Check the Medicare.gov coverage tool or call 1-800-MEDICARE for specific drug questions. Your doctor or the administering facility can confirm Part B coverage for professional-administered medications. Most self-administered prescriptions require Part D.
Dr. Usman is a medical content reviewer with 12+ years of experience in healthcare research and patient education. He specializes in evidence-based health information, medications, and chronic health topics. His work is based on trusted medical sources and current clinical guidelines to ensure accuracy, transparency, and reliability. Content reviewed by Dr. Usman is for educational purposes and does not replace professional medical advice.