The Biosimilar Switch: What Happens When Your Insurance Stops Covering Your Biologic
The Biosimilar Switch: What Happens When Your Insurance Stops Covering Your Biologic
5 minute read
You have been stable on your biologic medication for months, maybe years. Your condition is controlled. Your doctor is satisfied with how you are doing. And then you get a letter: your insurance plan is no longer covering your current medication. They will cover a biosimilar instead.
This is called non-medical switching, and it is becoming increasingly common as biosimilars enter the market for drugs like Humira, Enbrel, Stelara, and Remicade. Understanding what your rights are and what you can do if a forced switch puts your health at risk is important information to have before you simply accept the change.
What Is a Biosimilar?
A biosimilar is a medication that has been approved by the FDA as highly similar to an already-approved biologic drug (the "reference product"). Biologics are complex medications derived from living cells, typically used for conditions like rheumatoid arthritis, psoriasis, Crohn's disease, ulcerative colitis, and certain cancers.
Unlike generic drugs, which are chemically identical to their brand counterparts, biosimilars are not exact copies. They are required to have no clinically meaningful differences from the reference product in terms of safety, purity, and effectiveness, but they are produced by a different manufacturer using a different cell line and manufacturing process.¹
The FDA approval process for biosimilars is rigorous, and the agency has approved dozens of them in recent years. Most rheumatology, gastroenterology, and dermatology specialty societies acknowledge that biosimilars are generally appropriate for patients initiating therapy. The controversy arises around non-medical switching: moving a patient who is already stable on a reference biologic to a biosimilar purely for cost reasons.
Why Insurers Are Forcing the Switch
The economic logic is straightforward. Biosimilars typically cost 15 to 35 percent less than their reference biologics.² As biologic drugs come off patent, multiple biosimilar versions enter the market, and insurers, pharmacy benefit managers, and employer health plans see an opportunity to reduce drug spend.
The practice accelerated significantly after adalimumab (Humira) lost its exclusivity in January 2023. Nearly two dozen adalimumab biosimilars have entered or are entering the market, and many plans have already moved Humira to a non-preferred tier, raised its cost-sharing substantially, or removed it from the formulary altogether in favor of biosimilar versions.
For patients who are stable and doing well, the concern is not theoretical. Clinical literature documents cases where patients who were stable on a reference biologic experienced disease flares after a non-medical switch, though the frequency and severity of these events are debated in the medical literature.³ What is not debated is that the decision to switch a stable patient should ideally involve the prescribing physician, not just a formulary update.
Your Rights When Facing a Forced Switch
You have more options than simply accepting the switch. Here is what you can do.
Request a medical exception. If your prescribing physician has a documented clinical reason to continue the reference biologic (prior adverse reaction to the biosimilar, disease instability, a specific formulation need), they can submit a medical exception request to your insurer. The exception should specifically address why the biosimilar is not clinically appropriate for your situation, using language that mirrors the plan's coverage criteria.
Ask your doctor about interchangeability designation. The FDA has a specific designation called "interchangeable" that applies to biosimilars that have demonstrated they can be substituted for the reference product without increased safety or efficacy risk.⁴ Not all biosimilars have this designation. Whether your insurer is mandating a switch to an interchangeable or a non-interchangeable biosimilar may affect your appeal.
Check your state's biosimilar substitution laws. Most states have laws governing when a pharmacist can substitute a biosimilar for a prescribed biologic without prescriber approval. These laws typically require notification to the prescribing physician and, in some states, patient consent. If the switch was made without your doctor's involvement, your state law may have been violated.
Appeal on the basis of continuity of care. Many plans have continuity of care provisions that allow patients who are stable on a current therapy to continue it for a defined period, particularly following a formulary change mid-plan-year. A mid-year formulary change that removes your current medication may trigger these protections.
Look into manufacturer patient assistance programs. If your reference biologic is still available and your physician recommends it, the manufacturer may have programs that help cover costs for patients who cannot access it through insurance.
What This Means for You
If you received notice that your biologic is being removed from your formulary or replaced by a biosimilar, do not simply refill with the substituted drug without talking to your doctor first. That conversation matters, both medically and for the purpose of any appeal you might file.
If your physician agrees that the switch is clinically acceptable, that is a reasonable path. But if your physician has concerns, those concerns deserve to be documented and submitted formally before the switch takes place.
Ellen can help you understand your denial or formulary notice and build a medical exception request alongside your physician. Start here →
Frequently Asked Questions
Is a biosimilar safe to switch to?
For most patients starting a new biologic therapy, biosimilars approved by the FDA are considered safe and effective alternatives. The more complex question involves non-medical switching for patients who are already stable on a reference biologic. Your prescribing physician is the right person to evaluate your specific situation.
Can my pharmacist automatically substitute a biosimilar?
Pharmacists can substitute an FDA-designated interchangeable biosimilar for a prescribed biologic without prescriber approval in most states, though many states require notification to the prescriber and some require patient notification as well. If you were switched without your knowledge or your doctor's awareness, check your state's biosimilar substitution law.
What if I already switched and my condition got worse?
If you experienced a disease flare or change in health status after a non-medical switch, document it with your physician immediately. That documentation can support both a medical exception request and an appeal to return to the original reference biologic.
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