Does Medicare Part D cover Metformin?
Coverage, cost, and 2026 details for Metformin (metformin) under Medicare Part D.
Quick answer: Yes, Metformin is generally covered by Medicare Part D plans, typically on Tier 1 (preferred generic). Coverage details, copays, and restrictions vary by plan, so compare plans available in your area to find the best coverage for your medications.
What is Metformin?
Metformin is the most widely prescribed first-line medication for type 2 diabetes. It works by reducing how much sugar your liver produces and helping your body respond better to insulin. It's been used safely for decades and is available as a generic, so it's inexpensive.
Is Metformin covered by Medicare Part D?
Metformin is covered by every Medicare Part D plan and is almost always on Tier 1 (preferred generic), which has the lowest copay — often $0 to $10 for a 30-day supply. Some plans waive the deductible for Tier 1 generics.
Typical formulary tier
Metformin is most often listed on Tier 1 (preferred generic) of Part D formularies. The exact tier — and the copay — depends on the specific plan you're enrolled in.
How much does Metformin cost with Medicare Part D?
Without insurance, Metformin costs $10 to $20 per month at retail at retail pharmacies. With Medicare Part D coverage, you typically pay Typically $0 to $10 per month with Medicare Part D.
Your actual cost depends on:
- Your plan's deductible — up to $615 in 2026
- The tier Metformin is on in your plan's formulary
- Whether you've reached the $2,100 annual out-of-pocket cap
- Whether you qualify for Extra Help (Low-Income Subsidy)
- Whether you've enrolled in the Medicare Prescription Payment Plan (M3P), which spreads costs across the year
How to lower your Metformin costs
1. Compare Part D plans for your specific drugs
The same drug can cost dramatically different amounts on different plans. During the Annual Enrollment Period (October 15 – December 7), use the Medicare.gov Plan Finder to compare what Metformin would cost across every plan available in your ZIP code.
2. Check if you qualify for Extra Help
If your income is below approximately $23,475 (single) or $31,725 (married couple) in 2026, you likely qualify for Extra Help, which dramatically reduces what you pay for Metformin and all your medications. Learn about Extra Help →
3. Use the Medicare Prescription Payment Plan (M3P)
M3P doesn't lower your total cost, but it spreads your annual out-of-pocket costs into monthly installments — which can help if Metformin causes a big upfront pharmacy bill. Learn about M3P →
4. Look into Patient Assistance Programs
various (generic) may offer a Patient Assistance Program for people with limited income who don't qualify for Extra Help. These programs can provide free or deeply discounted medication directly from the manufacturer. Learn more about manufacturer programs →
5. Ask about alternatives
Talk to your doctor about whether a different medication — including a generic version or a similar drug in the same class — would work for you.
Alternatives to Metformin
Other medications used for type 2 diabetes include:
- Glucophage (brand-name metformin)
- Glumetza (extended-release)
- Riomet (liquid form)
- If metformin isn't tolerated: SGLT2 inhibitors, DPP-4 inhibitors, or GLP-1 agonists
Always discuss any medication change with your prescribing doctor.
Key facts about Metformin on Medicare
- One of the cheapest diabetes medications on Medicare Part D
- Almost always on Tier 1 (preferred generic) of Part D formularies
- Often available for $0–$10/month
Frequently asked questions about Metformin on Medicare
Does Medicare cover Metformin?
Yes, Metformin is generally covered by Medicare Part D plans, most often on Tier 1 (preferred generic). Coverage and costs vary between plans, so compare plans available in your area. Some plans require prior authorization.
How much does Metformin cost on Medicare Part D?
Costs typically range from Typically $0 to $10 per month with Medicare Part D. Your actual cost depends on your plan's deductible, the tier Metformin is on, and whether you've reached the $2,100 annual out-of-pocket cap.
Is there a generic version of Metformin?
Yes — generic versions are available and significantly cheaper. Most Part D plans cover the generic on a lower tier with lower copays.
What if my Part D plan doesn't cover this drug?
You have several options: (1) Switch to a different Part D plan during Annual Enrollment that covers Metformin, (2) Request a formulary exception from your current plan with your prescriber's support, (3) Ask your doctor about a covered alternative medication, or (4) Look into the manufacturer's Patient Assistance Program if you have limited income.
Compare your Part D options
Coverage and costs for this drug vary significantly between plans. Compare your options:
You can also visit Medicare.gov or call 1-800-MEDICARE