Medicare Part B covers costs relating to the diagnosis and treatment of medical conditions. Medicare Part D covers prescription drugs. Specific rules usually apply to both.
Medicare is the federal government’s insurance coverage for those ages 65 years and over or with certain medical conditions. Medicare packages have different parts that cover various aspects of medical treatment. Parts B and D are examples of this coverage.
This article will explain the differences between Medicare Part B and Part D, including those relating to costs and coverage.
Glossary of Medicare terms
We may use a few terms in this article that can be helpful to understand when selecting the best insurance plan:
- Out-of-pocket costs: An out-of-pocket cost is the amount a person must pay for medical care when Medicare does not pay the total cost or offer coverage. These costs can include deductibles, coinsurance, copayments, and premiums.
- Deductible: This is an annual amount a person must spend out of pocket within a certain period before an insurer starts to fund their treatments.
- Coinsurance: This is the percentage of treatment costs that a person must self-fund. For Medicare Part B, this is 20%.
- Copayment: This is a fixed dollar amount a person with insurance pays when receiving certain treatments. For Medicare, this usually applies to prescription drugs.
Medicare has four parts, which are called A, B, C, and D.
- Part A: This part covers inpatient care, hospice care, some home health and rehabilitation costs, and skilled nursing services. Part A is part of Original Medicare.
- Part B: This portion of Medicare covers medical services, such as doctor’s visits, durable medical equipment, and select prescription medications. A person can get Part B through Original Medicare and pay the premium to the federal government.
- Part C: If a person opts for Part C, also called Medicare Advantage, a private insurance company will fulfill Part B benefits. A Medicare Advantage plan must cover everything that Original Medicare covers, and it usually offers additional services.
- Part D: This part covers prescription drugs. The federal government requires that all people ages 65 years and over have prescription drug coverage equal to the basic policy that insurance companies offer. Private companies administer Part D plans.
Medicare Part B covers most doctor’s visits and services, as well as durable medical equipment, such as a wheelchair, crutches, or other assistive devices. It also covers some medications that Part D does not cover, such as the following:
- antigens that a doctor typically prepares
- blood clotting factors
- injectable or infused drugs
- erythropoiesis-stimulating agents, which doctors commonly use to treat end stage renal disease (ESRD)
- immunosuppressive drugs
- injectable medications for osteoporosis
- intravenous immunoglobulin at home
- oral medications for ESRD
- parental and enteral nutrition for IV and tube feeding
- vaccinations
Part B may cover other drugs, and a person can check their benefits for information about a specific medication.
Medicare Part D offers a wide range of benefits relating solely to prescription drugs. The plans must provide a listing, known as a formulary, of prescription drugs. A formulary must cover at least two drugs in each commonly prescribed category. Examples of these categories include medications to treat blood pressure and those for diabetes.
Formularies usually have tiers, with generic medications being the least expensive and premium or brand-name medications costing the most.
Both Part B and Part D play an essential role in protecting the health of older adults and those living with a disability. Medicare negotiates approved medical costs to help prevent unfair pricing by medical providers.
Coverage: Part B vs. Part D
There are differences in the coverage that each of Medicare’s four plans provides. The table below shows the differences between Part B and Part D:
| Comprehensive medical services | Limited coverage | Choice of providers | Low-cost pricing | Deductibles | Plan options | |
|---|---|---|---|---|---|---|
| Part B | Yes | Yes | Yes | No | Yes | No |
| Part D | No | No | No | Yes | Yes | Yes |
Costs: Part B vs. Part D
The costs for Part B and Part D vary depending on the plan and options.
Part B
A person must pay a monthly premium for Medicare Part B. The premiums usually change each year, but for 2024, the standard premium is $174.70.
In addition, Part B has a 2024 deductible of $240. A 20% coinsurance for most Medicare-approved services will apply after a person has paid the deductible. The coinsurance applies to certain services, including doctor’s visits and prescription drugs.
Part D
As private insurance companies administer Part D plans, the costs vary by plan and location. Some plans offer comprehensive prescription drug coverage. In 2024, the average Part D monthly premium is $34.70, which is a 6% increase from 2023, according to the Kaiser Family Foundation.
Medicare Advantage and Part D
A person may choose a Part D plan as part of a Medicare Advantage package. Private insurance companies offer Medicare Advantage plans, which results in varying benefits and costs among plans. The costs may include the monthly premium, deductibles, copayments, and coinsurances.
Eligibility and enrollment: Part B vs. Part D
Not everyone who turns 65 years of age must have Medicare. Some people may continue to work and choose to use their employer’s health insurance or their spouse’s insurance. In these instances, a person must send documentation to the Centers for Medicare & Medicaid Services (CMS) to show that they have appropriate medical insurance coverage.
If a person is no longer eligible for their own or their spouse’s employer’s health insurance, they may qualify for a special enrollment period during which they are still able to enroll for Medicare coverage.
A person should enroll in Medicare Parts B and D when they are first eligible. Waiting until after the initial enrollment period (IEP), which ends 3 months after the month in which a person turns 65, could result in additional penalties for the monthly premiums.
Unlike some private insurance plans, Medicare accepts all individuals who qualify without considering preexisting health conditions.
Extra Help
A person who meets the Medicare low-income criteria may qualify for Extra Help. The Extra Help program provides financial support to those who may need assistance to pay for prescription drugs.
Medicare resources
For more resources to help guide you through the complex world of medical insurance, visit our Medicare hub.
Part B and Part D are two Medicare parts that help beneficiaries pay their healthcare costs.
Medicare Part D pays for most at-home medications, while Medicare Part B generally pays for drugs that a person receives at a doctor’s office, hospital, or infusion center.
Part B also pays for additional services, such as doctor’s visits and some medical procedures.