Home infusion therapy, the delivery of medication intravenously or subcutaneously in a patient’s home, is a growing option for care. Medicare covers this service, but the coverage is complex because it does not fall under a single, unified benefit. The financial responsibility for the drug, equipment, and professional services is often split between Medicare Part B and Part D.
How Medicare Splits Home Infusion Services
Medicare coverage for home infusion therapy is complicated because it separates the necessary components—the drug, the equipment and supplies, and the professional services—into distinct benefit categories. This separation often leads to confusion for beneficiaries.
Medicare Part A has a limited role, generally covering therapy only if provided during a brief post-hospital stay under the home health benefit. The vast majority of outpatient home infusion needs are covered under Part B and Part D. Part B generally handles the equipment and professional services for certain drugs, while Part D is the primary payer for the cost of many home-infused medications. This division means a patient must manage costs and coverage rules across two separate parts of the Medicare program for a single therapy.
Medicare Part B Coverage for Equipment and Nursing
Medicare Part B, which covers medical services and Durable Medical Equipment (DME), is the primary source of coverage for the equipment and professional services associated with home infusion therapy. Part B covers the infusion pump, IV poles, tubing, and catheters as DME, provided the equipment is medically necessary and supplied by a Medicare-certified provider. The benefit also covers infusion drugs administered via the pump, but this applies only to a specific, limited list of medications.
The 21st Century Cures Act established a separate Part B benefit for professional services related to home infusion for certain drugs. Implemented in 2021, this benefit covers nursing services, patient education, training, and remote monitoring required for safe administration using an external DME pump. Professional services are now paid through a bundled payment to a qualified Home Infusion Therapy Supplier (HITS). The distinction remains between drugs covered under Part B—typically those administered in an office setting or via a DME pump—and those that are self-administered or not on the Part B list, which default to Part D coverage.
Navigating Medication Costs Through Part D
Medicare Part D, the prescription drug benefit, is the main source of coverage for the cost of the infusion medication itself, particularly for drugs that do not meet the strict Part B criteria. Many commonly infused drugs, such as intravenous antibiotics, are not covered under Part B, making Part D the default payer for the drug component. Part D plans, offered through private insurance companies, cover the ingredient cost of the drug and the pharmacy dispensing fees.
The financial responsibility for a Part D covered drug is governed by the plan’s formulary, its list of covered medications. Drugs are often placed on different cost tiers, resulting in greater out-of-pocket expenses. Part D coverage also involves an annual deductible and various phases of coverage, including the initial coverage phase and the coverage gap, often called the “donut hole,” which can significantly affect the final price of expensive infusion medications. This split forces beneficiaries to coordinate coverage across Part B and Part D, as the drug is covered by one plan but the necessary supplies and nursing care must be covered under a different part of Medicare.
Patient Eligibility and Out-of-Pocket Expenses
To be eligible for Medicare home infusion coverage, a patient must meet specific criteria, including a requirement for the therapy to be medically necessary and ordered by a physician. The physician must establish a detailed plan of care that specifies the medication, dosage, and the type and duration of the required professional services. Furthermore, all services and equipment must be provided by a certified Home Infusion Therapy Supplier (HITS) that is enrolled in Medicare.
For a beneficiary with Original Medicare, the financial structure typically involves several out-of-pocket costs. Under Part B, patients are generally responsible for the annual deductible, and then a 20% coinsurance of the Medicare-approved amount for the DME, supplies, and the professional services. Costs for Part D covered drugs vary significantly based on the specific plan, but generally involve a deductible, copayments, or coinsurance that change as the beneficiary moves through the coverage phases. Some beneficiaries with Medicare Advantage plans (Part C) may find these costs bundled differently, as Part C plans are required to cover all Original Medicare services but can offer different cost-sharing structures.