Key takeaways:
Biosimilars are complex medications made from natural or living sources. They treat health conditions such as cancer, rheumatoid arthritis, and diabetes. And they closely resemble a specific biologic, which is why they’re called biosimilars.
Most health insurance plans, including Medicare, cover biosimilars.
Biosimilars are typically lower-cost alternatives to their reference biologic.
Maybe you’re living with Type 2 diabetes or rheumatoid arthritis. Or you’ve been diagnosed with a type of cancer. If so, your healthcare professional may have prescribed a treatment called a biosimilar.
Biosimilars are different from over-the-counter medicines and typical prescription medications. They are made from living organisms or natural resources instead of chemicals.
Biosimilars have a quicker FDA-approval process and tend to cost less than their reference biologics, which also come from an array of living sources. Though not identical, biosimilars compare to biologics the way generic options can substitute for brand-name prescription medications.
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The Biologics Price Competition and Innovation Act (BPCIA) was part of the Affordable Care Act. The BPCIA provides an abbreviated approval pathway for biosimilars. The streamlined development process often results in lower medication costs. Biosimilars do not sacrifice safety and effectiveness.
What are biosimilars?
Biosimilars are complex medications approved by the FDA. These medications are used to treat many common and rare health conditions, including:
Are biologics and biosimilars different from traditional medications?
Think of biosimilars as the offspring of biologics. Biologics are medications made from living cells (human, plant, and other organisms). Because of this, they are hard to copy and produce in bulk.
Technically, biologics have no generic versions since generics are manufactured from chemicals. But a biosimilar closely resembles the structure and function of a brand-name medication.
Most of your medications, such as aspirin and antihistamines, are made of chemicals. These are called small-molecule drugs.
Biosimilars are more complex, large-molecule medications. Most must be stored at cold temperatures.
As the name indicates, biosimilars are highly similar to their biologic parents. But they’re not identical. This class of biological medications includes injectables such as insulins. Biosimilars are equally safe and effective — but typically at a lower cost. Some are fully interchangeable in the treatment of your chronic health condition.
An interchangeable biosimilar goes through extra steps during the FDA-approval process. This ensures that it can be substituted for the reference biologic medication. An interchangeable biosimilar isn’t significantly different or better. But it’s just as safe and effective as the regular biosimilar.
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Examples of common biosimilars include:
Cyltezo (adalimumab-adbm), an interchangeable biosimilar to Humira (adalimumab)
Renflexis (infliximab-abda), a biosimilar to Remicade (infliximab)
Zarxio (filgrastim-sndz), a biosimilar to Neupogen (filgrastim)
Kanjinti (trastuzumab-anns), a biosimilar to Herceptin (trastuzumab)
Semglee (insulin glargine-yfgn), an interchangeable biosimilar to Lantus (insulin glargine)
Zirabev (bevacizumab-bvzr) a biosimilar to Avastin (bevacizumab)
Does insurance cover biosimilars?
Many health insurance plans, including Medicare, cover biosimilars. But the medications covered by your formulary and how they’re reimbursed vary by plan. For example, Cigna is adding several Humira biosimilars to its preferred drug formulary.
A plan’s formulary has tiers. If your medication is in the highest tier, it’s typically a specialty, high-cost medication. You can expect higher out-of-pocket costs.
Alternatively, in the lower tiers, medications cost less. Check on your prescription coverage by finding out the answers to these questions:
Is there a copay? If so, how much?
Is there a coinsurance charge?
Is prior authorization necessary?
Will having this medication covered require step therapy?
There are two key reasons you might choose to switch from a biologic to a biosimilar:
Savings. Biosimilars typically cost less, according to the Association for Accessible Medicines.
Insurance coverage changes. Your health plan may require you to switch your medication if a lower-cost biosimilar is available.
You can also discuss your interest in changing medications with your prescriber. Together, you can talk about the recommended biosimilar and new treatment plan.
An interchangeable biosimilar may not have to go through your prescriber. A pharmacist may be able to substitute the less costly one for you, depending on the state you live in.
Which biosimilars are covered by insurance?
There is no universal coverage for biosimilars. Insurance coverage depends on your plan’s formulary. Many commercial (private) insurance plans cover these types of medications. Are you insured through your job? If so, contact your employer’s benefits administrator with coverage questions. Otherwise, call your health plan directly. Your coverage will vary by insurer, health plan, type of biosimilar, and drug formulary.
Does Medicare cover biosimilars?
Yes, your Medicare plan likely covers biosimilars. Your coverage will depend on:
The specific biosimilar medication you need
Your Medicare plan — whether you have original Medicare or Medicare Advantage
FDA approval
Biosimilars may be covered by Medicare Part B (medical insurance) or Medicare Part D (prescriptions).
For instance, Humira is used to treat a variety of autoimmune conditions. It is one of the world’s best-selling prescription medications. Humira lost its monopoly in 2023 and began to have competition from biosimilars. There are at least 10 now.
Most Medicare Part D plans included Humira biosimilars on their 2025 formularies, according to a U.S. Department of Health and Human Services Office of Inspector General report.
How are biosimilars reimbursed?
Biosimilars are reimbursed like other medications. But their unique characteristics as biological therapies are given consideration. For example, many are administered in a healthcare professional’s office or a hospital.
Both Medicare Part B and commercial insurance plans typically use buy-and-bill for biosimilar reimbursement. Under this model, the healthcare entity buys directly from the distributor. It then administers the specialty medicine and bills the insurance plan. The insurer will reimburse the healthcare entity for the treatment. This often includes an administration fee. You may be responsible for out-of-pocket costs, such as coinsurance, copays, and deductibles.
Why are biosimilars sometimes not covered by insurance?
Sometimes, biosimilars aren’t covered. This is because insurers limit the medications they include on their formulary. Several factors influence insurer decisions to limit biosimilar coverage, including:
Patient population
Plan size
Number of people with the health condition
Biosimilar competition (more than two on the market)
Partnerships with smaller pharmacy benefit managers, which may have less negotiating power
Frequently asked questions
The FDA has the authority to regulate biosimilars along with other medications. Before approving a biosimilar, the FDA checks for safety and effectiveness that’s comparable to its reference biologic. For example, both the biosimilar and the biologic must be made from the same type of living source, they must provide the same benefits when treating a particular condition, they must be given at the same strength and dosage, and they must not cause or worsen side effects.
Biosimilars are interchangeable if they can be substituted by a pharmacist without the prescriber’s approval in certain states. Not all biosimilars are interchangeable. An interchangeable biosimilar must meet more stringent safety and effectiveness criteria than other biosimilars.
State rules vary about whether a pharmacist can dispense an interchangeable biosimilar without a prescriber’s approval.
There were more than 80 FDA-approved biosimilars as of May 2026. These medications treat many conditions, including diabetes, cancer, and rheumatoid arthritis. Among the most recently approved biosimilars are:
Ennumo, which has the reference biologic Neulasta and treats low white blood cells
Langlara, which has the reference biologic Lantus and treats diabetes
Ponlimsi, which has the reference biologic Prolia and treats osteoporosis
The FDA has the authority to regulate biosimilars along with other medications. Before approving a biosimilar, the FDA checks for safety and effectiveness that’s comparable to its reference biologic. For example, both the biosimilar and the biologic must be made from the same type of living source, they must provide the same benefits when treating a particular condition, they must be given at the same strength and dosage, and they must not cause or worsen side effects.
Biosimilars are interchangeable if they can be substituted by a pharmacist without the prescriber’s approval in certain states. Not all biosimilars are interchangeable. An interchangeable biosimilar must meet more stringent safety and effectiveness criteria than other biosimilars.
State rules vary about whether a pharmacist can dispense an interchangeable biosimilar without a prescriber’s approval.
There were more than 80 FDA-approved biosimilars as of May 2026. These medications treat many conditions, including diabetes, cancer, and rheumatoid arthritis. Among the most recently approved biosimilars are:
Ennumo, which has the reference biologic Neulasta and treats low white blood cells
Langlara, which has the reference biologic Lantus and treats diabetes
Ponlimsi, which has the reference biologic Prolia and treats osteoporosis
The bottom line
Biosimilars are FDA-approved biologic therapies made from human, plant, or other living or natural cells. They are developed to treat many health conditions, including diabetes, cancer, and autoimmune diseases.
A biosimilar is often more affordable than its reference biologic medication. Most health insurance plans cover this class of medications. But coverage for specific biosimilars depends on your prescription plan’s formulary.
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References
Arthritis Foundation. (n.d.). Questions to ask your doctor about biologics & biosimilars.
Association for Accessible Medicines. (n.d.). 2025 savings report.
Association for Accessible Medicines. (2025). Report: 2025 U.S. Generic and Biosimilar Medicines Savings Report.
Cigna Healthcare. (2023). Cigna Healthcare adds new biosimilars to formularies to expand access, advance affordability.
Jeremias, S. (2023). Study reveals factors that dissuade commercial plans from covering biosimilars. The American Journal of Managed Care.
Patient Protection and Affordable Care Act. (n.d.). Biologics price competition and innovation act.
U.S. Department of Health and Human Services. (2025). Most Medicare Part D plans’ formularies included Humira biosimilars for 2025.
U.S. Food & Drug Administration. (n.d.). Prescribing interchangeable products.
U.S. Food & Drug Administration. (2022). Review and approval.
U.S. Food & Drug Administration. (2023). Biosimilar and interchangeable biologics: More treatment choices.
U.S. Food & Drug Administration. (2024). Biological product innovation and competition.
U.S. Food & Drug Administration. (2024). Biosimilars basics for patients.
U.S. Food & Drug Administration. (2026). Biosimilar product information.
Walker, L., et al. (2023). AbbVie’s blockbuster drug Humira finally loses its 20-year, $200 billion monopoly. NPR.
