Many people approaching Medicare eligibility compare Medicare Parts B and D to better understand how each type of coverage works. These two parts of Medicare serve different purposes and cover different categories of healthcare services.
Medicare Part B focuses on outpatient medical care and certain treatments provided in clinical settings. Medicare Part D is designed to cover prescription medications obtained through pharmacies or approved drug plans.
Most beneficiaries consider both parts when building a more complete healthcare coverage strategy. In this guide, we explain what each part covers, how they differ, and what to consider when deciding whether you need both.
Quick Comparison – Medicare Part B vs Part D
| Feature | Part B | Part D |
| Primary Coverage | Medical services, outpatient care | Retail prescription medications |
| Where You Use It | Doctor’s office, hospital, clinic | Pharmacy counter, mail order |
| 2026 Standard Premium | $202.90/month | $0–$100+/month (varies by plan) |
| Enrollment | Often automatic with Social Security | Requires choosing a specific plan |
| Late Penalty | 10% per 12-month delay | 1% × $38.99 (2026 Base Premium) × months delayed. Note: The Part D base beneficiary premium for 2026 is finalized at $38.99, a 6% increase from 2025. |
What Is Medicare Part B – Medical Insurance Coverage
Think of Part B as your gateway to medical care. This portion of Original Medicare handles the services you receive from healthcare providers, not the medications you purchase at a pharmacy.
Part B covers these essential services:
- Doctor visits and specialist consultations
- Outpatient procedures and preventive care
- Durable medical equipment (wheelchairs, walkers, oxygen)
- Lab tests and diagnostic screenings
- Mental health services and therapy
While Part B covers roughly 200 provider-administered drugs, the Inflation Reduction Act has introduced negotiated prices for 15 of the highest-spend Part D drugs (like Eliquis and Jardiance) and 15 Part B drugs for 2026. This means that for the first time, your costs for these specific medications are based on federally negotiated ‘Maximum Fair Prices,’ regardless of whether they fall under Part B or D.
For 2026, the standard Part B premium is $202.90 per month. Most beneficiaries will also pay an annual deductible of $283 before Medicare begins to pay. After that, you typically pay 20% of the Medicare-approved amount for most doctor services and outpatient care. As a New York-based broker, we also remind clients that NY DFS Regulation 187 ensures any supplemental coverage we recommend alongside Part B must strictly meet your “Best Interest” based on your specific financial profile.
What Is Medicare Part D – Prescription Drug Coverage
Part D fills the prescription medication gap left wide open by Part B. This coverage covers the retail drugs you pick up at your local pharmacy or order by mail.
Unlike Part B, which comes as one standardized plan, Part D requires you to choose from multiple private insurance plans. Each plan maintains its own formulary (the official list of covered medications) and sets its own premium within CMS guidelines.
Part D typically covers:
- Daily maintenance medications (blood pressure, cholesterol, diabetes pills)
- Antibiotics and short-term prescriptions
- Insulin and diabetes supplies
- Mental health medications
- Pain management prescriptions
The average Medicare Part D plan covers between 2,000 and 4,000 prescription medications across all therapeutic categories, compared to Part B’s limited list of roughly 200 drugs.
Part D premiums vary widely by plan and location, ranging from $0 to over $100 monthly in 2024. You’ll also encounter a multi-phase cost structure including deductibles, copays, and the coverage gap (commonly called the “donut hole”).
Under the Inflation Reduction Act (IRA), the 2026 Part D structure is simplified: once you spend $2,100 out-of-pocket (including your deductible), you enter the Catastrophic Phase and pay $0 for covered drugs for the rest of the year. The ‘Donut Hole’ is officially a thing of the past. Furthermore, all 2026 plans in New York must offer the Medicare Prescription Payment Plan (M3P), allowing you to spread these costs into capped monthly installments. Additionally, you now have the option to use the Medicare Prescription Payment Plan, which allows you to spread these out-of-pocket costs into monthly installments throughout the year rather than paying a large sum at the pharmacy counter.
Drug Coverage – The Key Difference Between Part B and Part D
Here’s where the confusion typically starts. Both parts cover medications, but the distinction lies in how and where you receive them.
The location-and-administration rule we’ve found most helpful: If you receive the medication at a doctor’s office, hospital, or clinic through a healthcare provider, Part B likely covers it. If you pick it up at a retail pharmacy counter or order it through the mail for self-administration at home, Part D covers it.
The list of drugs covered by Medicare Part B includes:
- Chemotherapy administered by IV infusion
- Rheumatoid arthritis biologics given by injection (Remicade, Orencia)
- Certain vaccines (pneumonia, hepatitis B)
- Blood clotting factors for hemophilia patients
- Injectable medications for end-stage renal disease
The list of drugs covered by Medicare Part D includes:
- Oral cancer medications (even for the same cancers Part B covers via infusion)
- Insulin and diabetes medications
- Heart medications (blood pressure pills, statins, blood thinners)
- Respiratory medications (inhalers, COPD treatments)
- Antibiotics and pain medications
Consider this scenario: A patient manages Type 2 diabetes with Metformin tablets picked up monthly at the pharmacy (Part D coverage). The same patient receives annual flu shots at their doctor’s office (Part B coverage). This person needs both parts working together to cover their complete healthcare needs.
Prescription drug coverage plays an important role in helping Medicare beneficiaries manage the cost of medications that are not covered under Part B. Many people choose to enroll in Part D coverage to help reduce out-of-pocket expenses for retail prescription drugs and maintain more comprehensive healthcare coverage.
Cost Comparison – What You’ll Pay for Part B vs Part D
Understanding the cost structures helps you budget accurately for Medicare coverage. Part B offers predictable costs, while Part D varies based on the plan you choose.
Part B costs (2024):
- Standard premium: $202.90/month
- Annual deductible: $283
- Typical cost-sharing: 20% coinsurance for most services
- No out-of-pocket maximum
Part D costs (2024):
- Premium: $0-$100+/month depending on plan
- Deductible: Up to $545 (some plans waive this)
- Cost-sharing: Varies by coverage phase and drug tier
- Out-of-pocket cap: $2,100 (The coverage gap, or ‘Donut Hole,’ has been fully eliminated under the Inflation Reduction Act.)
IRMAA Thresholds (2026):
High-income surcharges now apply if your modified adjusted gross income from two years ago exceeded $109,000 (individual) or $218,000 (married filing jointly).
Can you afford to skip one part and face potential coverage gaps? What happens when an unexpected health event creates immediate prescription needs you can’t afford out-of-pocket?
Do You Need Both Medicare Part B and Part D?
The short answer for most beneficiaries: yes, you need both parts for comprehensive protection.
Here’s why we recommend enrolling in both Part B and Part D during your Initial Enrollment Period:
Part B is practically essential because it covers fundamental medical services. Skipping Part B means paying 100% out-of-pocket for doctor visits, preventive care, and outpatient procedures. You’ll also face a permanent 10% premium penalty for each 12-month period you delay enrollment without creditable coverage.
Part D protects against prescription costs that can quickly become catastrophic. Even if you take no medications today, your healthcare needs can change suddenly.
Here’s a quick scenario we’ve encountered: A healthy 65-year-old delayed Part D enrollment because they only took daily vitamins. Fifteen months later, a cancer diagnosis created immediate needs for expensive oral chemotherapy drugs AND a permanent late enrollment penalty, adding $18 per month to their Part D premium for life. That’s $216 annually, every year, for delaying coverage they thought they didn’t need.
For 2026, the Part D late enrollment penalty is calculated using the national base beneficiary premium of $38.99. This penalty is 1% of the base premium ($0.39) for every month of delayed coverage, added to your monthly premium for as long as you maintain Part D coverage.
The consensus among Medicare counselors and State Health Insurance Assistance Programs (SHIPs) nationwide: Enrolling in both parts during your Initial Enrollment Period provides the comprehensive coverage most people need while avoiding permanent penalties.
Your Next Steps – Making the Right Medicare Choice
Comparing Medicare Part B and Part D is not about choosing one over the other. It is about understanding how each part works together to create more complete healthcare protection. Part B covers outpatient medical care and provider-administered treatments, while Part D helps cover the prescription medications you pick up at a pharmacy.
For many Medicare beneficiaries, both parts play an important role in managing healthcare costs and avoiding unexpected coverage gaps. The right combination depends on your prescriptions, medical needs, provider preferences, and long-term healthcare goals.
The key is to review your coverage options before enrollment deadlines and to understand how premiums, deductibles, formularies, and late-enrollment penalties can affect your healthcare expenses over time.
Need help comparing Medicare coverage options?
Contact Life143 to speak with a licensed Medicare advisor. We help individuals compare Medicare Part B, Part D, Medicare Advantage, and supplemental coverage options, review prescription drug coverage, verify provider access, and choose Medicare solutions that support both their healthcare needs and retirement budget with confidence.
Frequently Asked Questions
Does Medicare Part B cover prescription medications?
Medicare Part B covers a limited group of medications that are typically administered in a medical setting, such as injections, infusions, and certain outpatient treatments. Most retail prescription medications picked up at a pharmacy are covered under Medicare Part D.
Can I enroll in Medicare Part D without Medicare Part B?
In many cases, individuals enrolled in Medicare Part A and/or Part B may choose a standalone Medicare Part D prescription drug plan. Eligibility and enrollment rules can vary depending on the type of Medicare coverage a person has, including Original Medicare or Medicare Advantage plans.
What happens if I delay enrolling in Medicare Part B?
Delaying Medicare Part B enrollment without having other qualifying coverage may result in a late enrollment penalty and delayed access to outpatient medical coverage. Reviewing enrollment timelines can help individuals avoid potential gaps in healthcare coverage and unexpected out-of-pocket medical costs.
How does the Medicare Part D out-of-pocket cap affect Medicare Advantage plans?
Many Medicare Advantage plans include prescription drug coverage, and the new Medicare Part D out-of-pocket cap can help limit annual spending on covered medications. This feature may be particularly valuable for beneficiaries who take ongoing or high-cost prescriptions and want more predictability in their drug expenses.
