Why is the comparison with Medicare for VIVITROL 380 MG VIAL-DILUENT labelled estimated?

Beyond what the card shows, the records give these reasons: The Part D figure covers 2024-01-01 to 2024-12-31; the NADAC price is from the file of 2026-10-14. Part D spending basis, as the Part D record states it: Part D 2024 average spend per dosage unit for Vivitrol / Naltrexone Microspheres: all makers, strengths, forms and routes combined, claim-weighted; gross cost incl. dispensing fees and patient pay, before rebates. Unit taken as NADAC's EA. Joined on brand name.

Why does this page start at 1 unit (EA)?

NADAC prices this product per EA, and the FDA NDC Directory lists its NDC as dosage form “KIT” with no route. Only a tablet, capsule, lozenge or troche with route “ORAL”, or a tablet or film with route “SUBLINGUAL” or “BUCCAL”, starts at 30, and this is not one. NADAC’s EA for it may be the whole kit or one item in it, and the files do not say which. So the card starts at 1 unit (EA) rather than guess how many make up a fill; change it to match your prescription.

VIVITROL 380 MG VIAL-DILUENT

FDA nonproprietary name: naltrexone

For 1 unit (EA)

Pharmacies pay

$1,716.11 filed

1 × $1,716.11389 per EA

CMS NADAC · nadac-national-average-drug-acquisition-cost-20261014.csv · eff. 2026-09-23 · as of 2026-10-14 · retrieved 2026-10-17

Medicare Part D paid

$1,621.97 filed

1 × $1,621.97421 per EA, Part D average

Medicare's price is not your price.

Medicare Part D · DSD_PTD_RY26_P04_V10_DY24_BGM.csv · eff. 2024-01-01 to 2024-12-31 · as of 2026-06-25 · retrieved 2026-10-18

The spread

0.95× estimated

Medicare paid 5% less than pharmacies pay.

Part D averages every strength and form sold under “Vivitrol” / “Naltrexone Microspheres” into one figure, so it is not specific to this NDC.

OpenBill calculation · DSD_PTD_RY26_P04_V10_DY24_BGM.csv + nadac-national-average-drug-acquisition-cost-20261014.csv · NADAC eff. 2026-09-23 (file of 2026-10-14, retrieved 2026-10-17) · Part D 2024-01-01 to 2024-12-31 (file of 2026-06-25, retrieved 2026-10-18)

Cost-plus estimate

$1,978.53 estimated

$1,716.11 + $257.42 (15%) + $5.00 fee per fill = $1,978.53

This is a model, not a price any pharmacy quoted. Shipping is not included. How it is worked out

OpenBill calculation · nadac-national-average-drug-acquisition-cost-20261014.csv · NADAC eff. 2026-09-23 (file of 2026-10-14, retrieved 2026-10-17)

Open the interactive card Change the quantity, type what you were charged, and see every record in full.

What it is

VIVITROL 380 MG VIAL-DILUENT is how the CMS NADAC file names this product. The FDA NDC Directory lists it as naltrexone, under the trade name “VIVITROL”.

FDA gives its dosage form as kit.

The labeler, the company named on the label, is Alkermes, Inc.

FDA lists no Established Pharmacologic Class for it.

The NADAC file of 2026-10-14 prices it under one NDC (National Drug Code), 65757-0300-01.

NADAC classes it as a brand-name drug (rate-setting class B), and does not mark it as sold over the counter.

What pharmacies pay

Pharmacies pay $1,716.11 for 1 unit (EA) (1 × $1,716.11389 per EA, rounded to the cent), by the CMS NADAC file of 2026-10-14; that price took effect on 2026-09-23. That is what pharmacies pay their suppliers, not what they charge you.

NADAC’s explanation codes for it: 1, calculated from the most recently completed pharmacy survey; 5, calculated based on package size.

What NADAC measures · NADAC explanation codes

The NDC

65757-0300-01 · Alkermes, Inc. · $1,716.11389 per EA · eff. 2026-09-23 filed

What Medicare paid

Medicare Part D paid $1,621.97 for 1 unit (EA), at an average of $1,621.97421 per EA in 2024 (2024-01-01 to 2024-12-31) for “Vivitrol” and “Naltrexone Microspheres”, every strength and form sold under that name together (Medicare Part D Spending by Drug, file of 2026-06-25).

That average covers 44,521 Part D claims (fills, including refills) for 2024-01-01 to 2024-12-31, across every maker, strength and form under the name.

Medicare's price is not your price.

What Part D spending measures · Which Medicare figure OpenBill compares · How the spread is worked out

What to ask at the counter

None of these figures is your price: what you pay depends on your pharmacy, your insurance, coupons and discounts.

What is your cash price for 1 unit (EA)? Is it lower than what I would pay through my insurance?
If you have Medicare Part D: what is my plan’s copay or coinsurance for it? The Part D average on this page is not what you pay.
These are questions about price, not medical advice. Do not change or stop a medicine without talking to your prescriber or pharmacist.

Questions

Why is the comparison with Medicare for VIVITROL 380 MG VIAL-DILUENT labelled estimated?: Beyond what the card shows, the records give these reasons: The Part D figure covers 2024-01-01 to 2024-12-31; the NADAC price is from the file of 2026-10-14. Part D spending basis, as the Part D record states it: Part D 2024 average spend per dosage unit for Vivitrol / Naltrexone Microspheres: all makers, strengths, forms and routes combined, claim-weighted; gross cost incl. dispensing fees and patient pay, before rebates. Unit taken as NADAC's EA. Joined on brand name.
Why does this page start at 1 unit (EA)?: NADAC prices this product per EA, and the FDA NDC Directory lists its NDC as dosage form “KIT” with no route. Only a tablet, capsule, lozenge or troche with route “ORAL”, or a tablet or film with route “SUBLINGUAL” or “BUCCAL”, starts at 30, and this is not one. NADAC’s EA for it may be the whole kit or one item in it, and the files do not say which. So the card starts at 1 unit (EA) rather than guess how many make up a fill; change it to match your prescription.