Dalfampridine extended-release (Ampyra and others)

How Medicare covers it

Part D (forms used at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Dalfampridine (Ampyra) is a treatment to improve walking in adults with multiple sclerosis (MS). The label says this was shown by an increase in walking speed.

What it is for, in depth

The label says Ampyra is indicated to improve walking in adult patients with multiple sclerosis, shown by an increase in walking speed in clinical studies. It is prescribed for adults with MS who have walking difficulty; the label does not describe it as changing the underlying course of MS, only as a treatment to improve walking. It may be part of an MS care plan alongside other care your doctor directs, but the label extract itself does not place it in a sequence with other MS drugs. The only form and strength in the label is a 10 mg extended-release, film-coated tablet, supplied in bottles of 60.

How it works

Dalfampridine is a potassium channel blocker. The label says its exact therapeutic mechanism is not fully understood, but in animal studies it increased conduction of nerve signals in demyelinated axons (nerve fibers that lost their coating) by blocking potassium channels.

How it is taken

The label extract's dosage section is empty, so no dose schedule is stated there. The product in the label is a 10 mg extended-release tablet for twice-daily oral use, per the description and how-supplied sections. Follow your prescriber's exact directions and do not take extra doses, because seizure risk rises with higher doses, per the warnings.

Common side effects

The label extract lists the serious reactions of seizures and anaphylaxis (severe allergic reaction) rather than a full common-effects list. No common side-effect list is given in this extract, so ask your care team what to expect and report any new symptoms promptly.

Serious warnings

Ampyra can cause seizures, and the risk rises as the dose goes up; if a seizure occurs, stop the drug and do not restart it. Do not use it with other forms of 4-aminopyridine (4-AP, fampridine), because the active ingredient is the same. It can also cause anaphylaxis, a severe allergic reaction; if that occurs, stop it and do not restart it.

Who should be careful

Do not use Ampyra if you have a history of seizure, moderate or severe kidney impairment (creatinine clearance 50 mL/min or less), or a history of allergy to Ampyra or 4-aminopyridine, including anaphylaxis. Based on animal data, it may cause fetal harm in pregnancy, per the label extract. Older patients are more likely to have reduced kidney function, so kidney function should be known before starting, per the label.

Major interactions

OCT2 inhibitors taken at the same time may increase dalfampridine exposure and raise the risk of seizures, per the label extract. Tell your care team about all medicines you take, and never combine it with other 4-aminopyridine products.

Cost and saving notes

Dalfampridine is available as a generic extended-release tablet in addition to the brand-name Ampyra, and generic versions usually cost less than brand-name versions. If your Part D plan places it on a higher tier, you or your doctor can ask the plan for a tier exception. If you qualify for Extra Help, that program can lower your Part D premiums and drug costs. Part D also has an annual out-of-pocket cap that limits what you pay for covered drugs in a year.

Why it is in its tier

Dalfampridine extended-release (Ampyra and others) sits on Tier 3 in 80.24% of the plans that list it (3700 of 4611 listing plans). Tier 3 is the preferred brand tier — mid-level copays or coinsurance. The data-visible drivers: It is sold both as a brand product and in generic form, and the CMS dashboard puts its average Part D spending at about $2,819 per beneficiary for 2024 — a mid-cost drug, which matches where plans place it. It is listed by 83.91% of Part D plans. The tier shown is the most common one; individual plans vary.

Sources

• AMPYRA (DALFAMPRIDINE) TABLET, FILM COATED, EXTENDED RELEASE [MERZ PHARMACEUTICALS, LLC] — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus

What official patient guides say

In daily life, dalfampridine is an extended-release tablet taken twice a day about 12 hours apart at about the same times each day, swallowed whole without splitting, chewing, dissolving, or crushing. MedlinePlus notes it is not stocked in regular pharmacies and is obtained by mail from a specialty pharmacy, and that it may take 6 weeks or longer to feel the full benefit for walking. It helps only while you keep taking it, so continue as directed and do not stop without talking to your doctor. Read the Medication Guide you receive with each fill and keep all doctor and lab appointments.

Source: MedlinePlus

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is 0.36657 per unit (DALFAMPRIDINE ER 10 MG TABLET) — about nan for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-07

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 4,611 list Dalfampridine extended-release (Ampyra and others) — 83.9% of plans. Most of those plans put it on Tier 3: 3,700 plans, 80.2% of the plans that list it. Other plans place it on Tier 2 (498 plans), Tier 1 (389 plans) or Tier 4 (24 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 3; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 3; Aetna Medicare Value Plus (PPO) puts it on Tier 3. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.