What Is a Biosimilar
A biosimilar is a biologic medication manufactured to be highly similar to an FDA-approved biologic drug already on the market. Unlike generic drugs (which are chemical copies of smaller molecules), biosimilars are derived from living cells and cannot be exact copies. The FDA requires biosimilars to demonstrate analytical, animal study, and clinical data showing they are as safe and effective as the original biologic. Biosimilars typically cost 10-35% less than their reference biologics, which affects how insurance companies cover them and how your costs are calculated on your Explanation of Benefits (EOB).
How Biosimilars Affect Your Insurance Claims
Insurance companies use biosimilars as cost-control tools. When a cheaper biosimilar becomes available, your insurer may place the original biologic in a higher cost-sharing tier on the formulary or require prior authorization before approving the reference drug. This means your claim can be denied if your doctor prescribes the brand-name version when a biosimilar exists on your plan's formulary.
On your EOB, you'll see the approved drug listed with your cost-sharing amount. If you're denied coverage for the original biologic, your denial letter should cite "formulary restriction" or "cost management." This is where you have leverage: if your doctor documents medical necessity (stating why the biosimilar won't work for you), you can file an internal appeal with specific clinical reasons.
Prior Authorization and Appeals
Most biosimilars require prior authorization. Your pharmacy submits the request, and the insurance company's pharmacy team reviews it within 24-72 hours. If denied, you have the right to an internal appeal (usually 30 days) and then an external appeal through your state's independent review organization if you lose internally.
For internal appeals, your doctor should submit clinical documentation showing the biosimilar caused adverse effects, allergic reactions, or failed to achieve clinical outcomes. States like New York and California have specific regulations (New York Insurance Law Article 49-B; California Health Code 1367.01) requiring insurers to provide clear denial reasons and timelines for appeals. Some states mandate external appeals be completed within 72 hours for urgent cases.
Medical necessity is your strongest argument in a denial fight. If your physician states you had a documented reaction to the biosimilar or that your condition requires the specific reference biologic, include that documentation in your appeal letter. Insurance companies must consider peer-reviewed literature supporting your doctor's position.
Key Considerations
- Interchangeability matters: The FDA distinguishes between "biosimilars" and "interchangeable biosimilars." Only interchangeable biosimilars can be substituted by a pharmacist without doctor approval. Check your EOB or formulary to see which classification applies to your drug.
- Formulary placement: Review your formulary to see if your biologic or its biosimilar is covered. A lower tier usually means lower out-of-pocket costs for you.
- Specialty pharmacy requirement: Most biologics and biosimilars are distributed through specialty pharmacies, not retail chains. This affects where you pick up your medication and how your claims are processed.
- Cost-sharing vs. deductibles: Some plans apply biosimilars differently. You may hit your deductible first, or pay a coinsurance percentage. Check your EOB to understand your specific cost structure.
- Step therapy: Many insurers require you to try the biosimilar first before approving the reference biologic. If the biosimilar fails, you can appeal with clinical evidence.
Common Questions
- What should I do if my insurance denies my biologic claim because a biosimilar is available? Request your insurer provide the specific reason in writing. File an internal appeal within 30 days with your doctor's statement about medical necessity. If your doctor states you need the reference biologic for clinical reasons (prior adverse event, lack of efficacy with biosimilar, or documented allergy), include that in your appeal letter.
- Is a biosimilar as effective as the original biologic? The FDA requires biosimilars to demonstrate equivalent safety and effectiveness through clinical trials. However, individual patient response can vary. If you've tried a biosimilar and it didn't work, document this response and use it in an appeal for the reference biologic.
- Will I pay more out-of-pocket for the reference biologic if I reject the biosimilar? Possibly. If your plan places the biosimilar in a lower tier, choosing the reference biologic may mean higher cost-sharing. Request a cost comparison from your specialty pharmacy and insurer before deciding.