How Much Does Avonex Cost With Medicare?
Avonex (Interferon Beta-1a) costs an average of $5,074 per Medicare Part D claim, with total Medicare spending of $345.0M in the latest year. A generic version is available, which may reduce out-of-pocket costs.
Key Facts: Avonex Cost
- Medicare Part D avg
- $5,074/claim
- Likely Part D tier
- Tier 4-5 (specialty)
- Annual cost/patient
- $55,645
- Generic available
- Yes — Interferon Beta-1a
- Manufacturer
- Biogen
- Treats
- Multiple Sclerosis
- YoY price change
- -22.4%
Source: CMS Medicare Part D Spending Dashboard. Tier placement inferred from typical formulary norms — confirm with your specific Part D plan.
Avonex Medicare Coverage & Out-of-Pocket Cost
Avonex is covered under Medicare Part D, with the program paying an average of $5,074 per prescription fill. Avonex typically falls on Tier 4-5 (specialty) of standard Part D formularies. Specialty drugs use coinsurance (25-33% of plan-negotiated price), not flat copays. The 2025 Part D annual out-of-pocket cap is $2,000.
Your actual out-of-pocket cost depends on three factors: (1) formulary tier — your plan's specific placement; (2) deductible status — most plans require you to meet up to a $590 deductible (2025) before copays kick in; (3) coverage phase — initial coverage, then the donut hole was eliminated in 2025, replaced by a hard $2,000 annual out-of-pocket cap under the Inflation Reduction Act. Once you hit $2,000 in true out-of-pocket spending, the rest of your Part D drugs are free for the year.
Because generic Interferon Beta-1a is available, the single biggest savings move is asking your pharmacist about generic substitution. Generics typically sit on Tier 1 with copays under $10, vs Tier 2-3 placement for brand-name Avonex. Most states allow automatic substitution unless your prescriber writes "dispense as written."
For cash-pay or commercial insurance scenarios, compare prices using GoodRx, SingleCare, or Cost Plus Drugs before filling — discount-program prices sometimes beat Part D copays for lower-cost generics.
Avonex is manufactured by Biogen and prescribed primarily for Multiple Sclerosis. In the most recent Medicare Part D data, 68,000 claims were filed for 6,200 unique beneficiaries, at an average cost of $5,074 per claim. Average annual cost per beneficiary is $55,645.
Year over year, Medicare spending on Avonex has decreased by -22.4%. Because a generic version of Interferon Beta-1a is available, patients can often substitute to reduce out-of-pocket costs. Its patent expires 2023-01-31.
Key Data
| Metric | Value |
|---|---|
| Avg Cost Per Claim | $5,074 |
| Total Medicare Spending | $345.0M |
| Total Claims | 68,000 |
| Beneficiaries | 6,200 |
| Generic Available | Yes |
| Year-Over-Year Change | -22.4% |
Other Drugs for Multiple Sclerosis
Frequently Asked Questions
Medicare Part D pays an average of $5,074 per claim for Avonex. Avonex is typically placed on Tier 4-5 (specialty) of standard Part D formularies. Specialty drugs use coinsurance (25-33% of plan-negotiated price), not flat copays. The 2025 Part D annual out-of-pocket cap is $2,000. As of 2025, total annual out-of-pocket on Part D is capped at $2,000 under the Inflation Reduction Act.
Yes. Avonex appears in Medicare Part D claims data, with 6,200 beneficiaries filling 68,000 prescriptions in the latest year. Specific coverage depends on your plan's formulary — call the number on your insurance card or check the plan's Summary of Benefits to confirm prior authorization, step therapy, or quantity limit requirements.
Avonex (Interferon Beta-1a) costs an average of $5,074 per Medicare Part D claim, with total Medicare spending of $345.0M in the latest year. A generic version is available, which may reduce out-of-pocket costs.
Yes. A generic version of Interferon Beta-1a is available, which typically costs 80-95% less than brand-name Avonex. Ask your pharmacist about generic substitution — most state laws allow automatic substitution unless your prescriber writes "dispense as written."
Medicare beneficiaries cannot use manufacturer copay cards (anti-kickback statute), but several options exist: (1) Apply to charity copay foundations like the PAN Foundation, NeedyMeds, HealthWell Foundation, or Patient Advocate Foundation — many cover multiple sclerosis drugs; (2) Ask your prescriber about therapeutic alternatives in the same drug class that may be on a lower tier; (3) For some drugs, paying cash via GoodRx or Cost Plus Drugs can beat your Medicare copay — always compare before filling; (4) If your income is below 150% of the federal poverty level, you may qualify for the Medicare Extra Help (Low-Income Subsidy) program, which reduces Part D costs to near-zero.
Avonex is manufactured by Biogen. The FDA application number is BLA125057.
Avonex (Interferon Beta-1a) is primarily prescribed for Multiple Sclerosis.
Medicare Part D spending on Avonex has decreased -22.4% year over year. Total program spending reached $345.0M in the latest reporting year.
Avonex (Interferon Beta-1a) costs an average of $5,074 per Medicare Part D claim, with total Medicare spending of $345.0M in the latest year. A generic version is available, which may reduce out-of-pocket costs.
This answer pulls from CMS Medicare Part D Drug Spending data, the authoritative federal source for U.S. Medicare prescription-drug pricing. The headline number above is the direct answer; what follows is the additional context most readers need to use the answer for a real decision rather than just a fact lookup.
For readers turning this answer into action: cross-reference against the underlying CMS Medicare Part D Drug Spending data record before acting on time-sensitive decisions. The site renders the data as it was published; subsequent revisions can shift the picture, and the live federal data is always the authoritative current reference.
Source: CMS Medicare Part D Spending, 2026.