Janumet is Merck's fixed-dose combination tablet of sitagliptin (a DPP-4 inhibitor) and metformin hydrochloride (a biguanide), prescribed together for adults with type 2 diabetes when both active ingredients are clinically appropriate. Merck markets two forms: Janumet (immediate-release, taken twice daily with meals) and Janumet XR (extended-release, taken once daily). The drug combines the blood-sugar-lowering mechanisms of sitagliptin, which prolongs the action of incretin hormones after meals, with metformin, which reduces hepatic glucose output and improves insulin sensitivity. Januvia contains sitagliptin alone. Janumet packages that same ingredient alongside metformin for patients already on both drugs or those for whom combination tablet adherence is preferred.
Janumet's list price reached roughly $527 per month by 2026, compared to the ingredient cost of metformin alone at under $15 per month. The combination premium reflects Merck's pricing of the sitagliptin component, not the metformin. Two simultaneous forces are pushing Janumet costs down in 2026 and 2027: the arrival of generic sitagliptin/metformin tablets under patent settlement agreements effective May 2026, and the Inflation Reduction Act Round 2 negotiation that set a Maximum Fair Price of $80 per month for Janumet through Medicare Part D, effective January 1, 2027. That 85 percent reduction from the 2024 list price is the largest percentage cut among all 15 Round 2 IRA-negotiated drugs. For context, Janumet's companion molecule Januvia received a 79 percent IRA Round 1 reduction effective January 2026, bringing its Medicare price to $113 per month. Patients enrolled in Medicare Part D who are waiting for the January 2027 Janumet Maximum Fair Price should confirm their plan's current 2026 formulary tier and copay for the drug.
Patients with Medicare Part D who need both sitagliptin and metformin should also ask their prescriber whether the combination tablet offers any clinical advantage over taking generic sitagliptin (already at the $113 IRA Round 1 Maximum Fair Price since January 2026) alongside generic metformin (under $15 per month at retail). Splitting the drugs may cost less in 2026 than using Janumet before the 2027 Round 2 price takes effect. This page covers 2026 pricing for brand Janumet and generic sitagliptin/metformin by pharmacy, the Merck Helps patient assistance program with an income eligibility table based on the 2026 federal poverty level, Medicare Part D coverage details, and what Medicaid and commercially insured patients can expect to pay. Patients who qualify for Medicaid typically pay $1 to $4 per prescription for the combination. Related pages: Januvia cost covers the single-ingredient sitagliptin; metformin cost covers the stand-alone biguanide.
What Janumet Costs by Point of Pay (2026)
The price you pay depends almost entirely on WHERE you pay. The same janumet can cost many times more at a hospital than at your local pharmacy:
2026 Janumet Price by Point of Pay| Where you pay | Typical cost | Notes |
|---|
| Retail pharmacy, brand Janumet (cash, no insurance) | $527/month (list price) | WAC list price for 60 tablets (30-day supply); GoodRx coupon reduces brand to $336 to $359 at major chains |
| Retail pharmacy, generic sitagliptin/metformin (cash, with coupon) | $110 to $160/month | Generic launched May 2026 under patent settlement; GoodRx coupon prices start around $110 at CVS and Walgreens |
| Medicare Part D (2026, standard benefit) | Varies by plan tier; capped at $2,000/year OOP | No drug-specific monthly cap in 2026; IRA Round 2 MFP of $80/month takes effect January 1, 2027 |
| Inpatient hospital facility charge | $150 to $700/stay | Facility markup on oral tablets dispensed during admission; typical acquisition cost is under $10 for the generic |
| Medicaid | $1 to $4/prescription | Nominal state copay; coverage and prior authorization requirements vary by state formulary |
Brand Janumet list price based on 2026 Merck WAC disclosures. Generic prices from GoodRx (May 2026). Medicare IRA Round 2 MFP of $80/month takes effect January 1, 2027. Inpatient ranges based on CMS Hospital Price Transparency data.
Source: Merck WAC disclosures 2026, GoodRx (goodrx.com/janumet), CMS Medicare Drug Price Negotiation Program
Why Hospitals Charge So Much
Janumet is an oral combination tablet with a drug acquisition cost well under $10 per day at 2026 generic prices. When a patient is admitted to a hospital and their home diabetes regimen is continued, the hospital dispenses medications from its own pharmacy and bills at facility rates. Those rates layer drug acquisition cost with pharmacy staff time, dispensing systems, formulary management overhead, and general facility fees. An oral tablet that costs the hospital under $10 per day can appear as $150 to $700 on a facility bill for a week-long admission.
Janumet is a Part D drug, not a Part B drug. Medicare does not publish an ASP (Average Sales Price) for sitagliptin/metformin combinations and there is no J-code for this oral tablet. Outpatient coverage runs through Part D prescription drug plans, not Part B medical benefit. For inpatient stays, Medicare DRG bundled payments typically include drug costs; the hospital absorbs sitagliptin/metformin from the DRG rate. However, patients may still see a line item for Janumet on an itemized inpatient bill, which may represent a documentation charge rather than a separately billable drug. Request an itemized bill and verify that any sitagliptin/metformin charges fall within your actual admission dates and that the dispensed product matches your prescription.
Three structural factors drive the gap between what Janumet costs at a retail pharmacy and what appears on a hospital bill. First, hospitals purchase drugs at contract rates but are permitted to mark up for handling. Second, the DRG bundling does not prevent hospitals from listing individual drug line items on patient-facing bills, even if Medicare is absorbing those costs. Third, if a brand Janumet tablet was dispensed when a cheaper generic was available, ask the hospital pharmacy to confirm which product was actually dispensed and whether the generic would have been substituted under your plan's formulary. The CMS Hospital Price Transparency rule requires hospitals to publish standard charges for all drugs, so you can compare your bill against the hospital's published price file.
Patient Assistance Programs
Merck operates the Merck Helps patient assistance program for Janumet, which provides the medication free of charge to qualifying uninsured US residents. The standard income threshold is 400 percent of the federal poverty level, meaning a single person earning up to $63,840 in 2026 may qualify. Patients with any prescription insurance, including Medicare Part D, Medicaid, or private plans, do not qualify for Merck Helps for Janumet. Separately, the availability of generic sitagliptin/metformin at $110 to $160 per month as of May 2026 means many patients now have a low-cost pharmacy option even without a formal patient assistance program. A manufacturer coupon for Janumet is available for commercially insured patients, capping copays at $5 per prescription up to a maximum savings of $150 per prescription, but this coupon cannot be used with Medicare or Medicaid.
Patient assistance programs for Janumet| Manufacturer program | Cost / Benefit | How to apply |
|---|
| Merck Helps (Merck Patient Assistance Program) for Janumet | Free Janumet for uninsured patients with household income at or below 400% FPL (approximately $63,840 for an individual in 2026) | merckhelps.com/JANUMET |
| Janumet Savings Coupon (commercially insured patients) | Copay reduced to as low as $5 per prescription, up to $150 savings per fill; for commercially insured patients only; not valid with Medicare or Medicaid | janumetxr.com/special-offers |
| Generic sitagliptin/metformin via GoodRx | $110 to $160/month at CVS or Walgreens with GoodRx coupon (generic, launched May 2026) | goodrx.com/sitagliptin-metformin |
| NeedyMeds Drug Discount Card | Variable discount accepted at most US pharmacies; no income requirement; cannot be used with insurance | needymeds.org |
Manufacturer savings cards and coupons are not available to Medicare, Medicaid, TRICARE, or VA beneficiaries by federal law (anti-kickback statute, 42 U.S.C. § 1320a-7b). If you have government insurance, apply for the Merck Helps patient assistance program instead. Merck Helps uses 400% FPL as its income threshold. Apply by phone at (800) 727-5400 or online at merckhelps.com. The IRA Round 2 Maximum Fair Price of $80 per month for Janumet takes effect January 1, 2027 for Medicare Part D enrollees, replacing any coupon-based pricing for that population.
Source: merckhelps.com/JANUMET, janumetxr.com/special-offers, NeedyMeds.org (needymeds.org), GoodRx (goodrx.com/sitagliptin-metformin)
Medicare Part D
Janumet is a Medicare Part D drug. Coverage runs through Medicare prescription drug plans, not Medicare Part B medical benefit. As of January 1, 2026, Janumet does not yet have a drug-specific Monthly cap or IRA-negotiated Maximum Fair Price under Part D; those protections apply to Round 1 IRA drugs like Januvia, Jardiance, and Eliquis. The 2026 Part D annual out-of-pocket cap of $2,000 does apply to Janumet: once you have paid $2,000 across all Part D drugs combined in a calendar year, your cost share drops to $0 for the rest of that year. At typical 2026 Part D copay rates for a mid-tier brand drug, the $2,000 annual cap may be reached in 10 to 14 months for patients using Janumet as their only expensive Part D drug.
Beginning January 1, 2027, Medicare Part D enrollees will benefit from the IRA Round 2 Maximum Fair Price for Janumet. CMS negotiated this price at $80 per 30-day supply, down from the pre-negotiation list price of approximately $526 per month. That represents an 85 percent reduction and is the largest percentage cut among all 15 Round 2 negotiated drugs. No Medicare Part D plan will be permitted to charge an enrollee more than $80 for Janumet at an in-network pharmacy after January 1, 2027. Patients currently enrolled in Medicare Part D who are paying higher than generic-equivalent rates for Janumet in 2026 should review whether their plan's formulary tier for brand Janumet, or the availability of the generic sitagliptin/metformin combination, produces a lower 2026 out-of-pocket cost ahead of the 2027 MFP effective date.
Janumet does not qualify for the $35 per month insulin cap that applies to insulin products under the Inflation Reduction Act. The $35 insulin cap covers insulin products specifically. Janumet and its companion Januvia are DPP-4 inhibitors, not insulin, so they fall under the general Part D cost-sharing structure in 2026 and under the drug-specific IRA Maximum Fair Price in 2027 for Medicare beneficiaries. Prior authorization is standard for Janumet on most Medicare Part D and commercial formularies. Check your plan's prior authorization requirements before filling.
Common Janumet Billing Errors
Janumet and generic sitagliptin/metformin are oral tablets with no HCPCS J-code and no Part B billing pathway. Still, several billing and insurance errors appear on claims and hospital bills for this drug class:
- Brand Janumet billed when generic sitagliptin/metformin was dispensed: verify the dispensed drug name and NDC number on your itemized bill; the generic and brand carry different NDC codes and different prices
- Charged at Janumet combination price when only separate sitagliptin or only metformin was dispensed: confirm the exact dispensed product against the prescription
- Inpatient facility charge applied to medication the patient brought from home: hospitals cannot bill for drugs the patient self-supplied if those drugs were not dispensed from the hospital pharmacy
- Prior authorization denial not appealed: most Part D plans and commercial plans require prior authorization for Janumet; if your claim was rejected for missing PA, ask your prescriber's office to file the PA request before refilling
- IRA Round 2 MFP not honored after January 2027: Medicare Part D enrollees charged more than $80 for brand Janumet after January 1, 2027 should contact their plan's member services and request a coverage determination
Frequently Asked Questions
Is there a generic for Janumet in 2026?
Yes, as of May 2026. Generic sitagliptin/metformin hydrochloride immediate-release tablets began entering US pharmacies in May 2026 under patent settlement agreements Merck reached with multiple generic manufacturers. These are AB-rated equivalents, meaning pharmacists can substitute them for brand Janumet. GoodRx prices for the generic start around $110 per month. Janumet XR (extended-release) generic is expected in July 2026 or later under separate settlement terms. Ask your pharmacist specifically for generic sitagliptin/metformin phosphate tablets to ensure substitution. Zituvimet (sitagliptin free base plus metformin, from Zydus) is a separate branded product and is not a pharmacy-substitutable generic for Janumet.
What is the IRA negotiated price for Janumet in 2027?
Under the Inflation Reduction Act Round 2 Medicare drug price negotiations, CMS set a Maximum Fair Price of $80 per 30-day supply for Janumet, effective January 1, 2027. This represents an 85 percent reduction from the pre-negotiation list price of approximately $526 per month and is the deepest percentage cut among all 15 drugs in the Round 2 negotiation. No Medicare Part D plan may charge an enrollee more than $80 for brand Janumet at an in-network pharmacy after that date. For 2026, Medicare Part D enrollees pay their plan's standard formulary tier rate; the $80 Maximum Fair Price does not apply until January 1, 2027.
How do I apply for the Merck Helps patient assistance program for Janumet?
Call (800) 727-5400 or visit merckhelps.com/JANUMET to start the Merck Helps application. You will need: your Janumet prescription, proof of US residency, documentation of household income (most recent tax return or 4 pay stubs), your prescriber's signed section of the application form, and a statement that you have no prescription drug insurance. For a single person in 2026, income must be at or below $63,840 (400 percent of FPL). Processing typically takes 7 to 14 business days. If approved, Merck ships Janumet free to your home or prescriber's office. Patients with any prescription insurance, including Medicare Part D or Medicaid, do not qualify.
Can I use the Janumet savings coupon with Medicare?
No. Federal anti-kickback law (42 U.S.C. § 1320a-7b) bars manufacturer copay coupons and savings cards from being used by anyone with Medicare, Medicaid, TRICARE, or VA coverage. The Janumet Savings Coupon is for commercially insured patients only and reduces copays to as low as $5 per prescription, up to $150 savings per fill. If you have Medicare Part D, you cannot use the manufacturer coupon; instead, check your plan's formulary tier for Janumet or apply for the Merck Helps patient assistance program if you are below the income threshold.
What is the difference between Janumet, Januvia, and Janumet XR?
Januvia contains sitagliptin alone (25 mg, 50 mg, or 100 mg tablets, taken once daily). Janumet combines sitagliptin with metformin HCl in one tablet, taken twice daily with meals; available as 50 mg/500 mg and 50 mg/1000 mg. Janumet XR combines the same ingredients in an extended-release form, taken once daily. All three are made by Merck. Under IRA Round 1, Januvia received a Maximum Fair Price of $113 per month effective January 2026. Under IRA Round 2, Janumet and Janumet XR received a Maximum Fair Price of $80 per month effective January 2027. Generic sitagliptin launched May 2026 for Januvia-equivalent products. Generic sitagliptin/metformin immediate-release launched May 2026 for Janumet-equivalent products.
What does Janumet cost without insurance at the pharmacy counter in 2026?
Without insurance, brand Janumet (50 mg/500 mg or 50 mg/1000 mg, 60 tablets for a 30-day supply) costs approximately $527 at the list price in 2026. With a GoodRx coupon, cash prices at major chains run $336 to $359 per month. Generic sitagliptin/metformin, which launched in May 2026, costs approximately $110 at CVS and Walgreens with a GoodRx coupon, and as low as $110 to $160 across other chains. Costco's cash price for brand Janumet runs $380 to $420 per month. Walmart accepts GoodRx coupons and prices brand Janumet around $348 with a coupon.
Does Medicare Part D cover Janumet?
Yes. Janumet is a Part D drug covered through Medicare prescription drug plans. In 2026, most Part D plans include Janumet on their formulary, typically on a higher cost-sharing tier with prior authorization required. The 2026 annual Part D out-of-pocket cap of $2,000 applies: once you spend $2,000 across all Part D drugs combined in a calendar year, your cost drops to $0 for the rest of the year. Starting January 1, 2027, the IRA Round 2 Maximum Fair Price of $80 per month takes effect, capping what any Medicare Part D plan may charge for brand Janumet. Janumet does not have the $35 per month insulin-specific cap that applies only to insulin products.
What if my insurance denies coverage for Janumet?
If your plan denies Janumet coverage, first request the written denial with the specific reason code. Common reasons include step therapy (requiring you to try separate generic sitagliptin plus generic metformin first) and prior authorization not filed. Ask your prescriber to file a prior authorization with supporting documentation of medical necessity. If that is denied, escalate to a formal appeal within 60 days and ask your prescriber for a peer-to-peer review with the plan's medical director. As a parallel option, the generic sitagliptin/metformin combination (available May 2026) is typically covered at a lower tier. If all else fails, the Merck Helps program can provide free Janumet for uninsured patients at or below 400 percent FPL.
