Why is the comparison with Medicare for DIFLUNISAL 500 MG TABLET 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 Diflunisal / Diflunisal: 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 generic name.

DIFLUNISAL 500 MG TABLET

For 30 tablets

Pharmacies pay

$31.94 filed

30 × $1.06451 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

$26.16 filed

30 × $0.87187 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

0.82× estimated

Medicare paid 18% less than pharmacies pay.

Part D averages every strength and form sold under “Diflunisal” 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

$41.73 estimated

$31.94 + $4.79 (15%) + $5.00 fee per fill = $41.73

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

DIFLUNISAL 500 MG TABLET is how the CMS NADAC file names this product. The FDA NDC Directory lists it as diflunisal.

FDA gives its dosage form as tablet, film coated and its route as oral.

Its labelers, the companies named on the label, are Teva Pharmaceuticals USA, Inc., Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. and Chartwell RX, LLC.

FDA’s Established Pharmacologic Class for it is Nonsteroidal Anti-inflammatory Drug.

The NADAC file of 2026-10-14 prices it under 6 NDCs (National Drug Codes).

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

What pharmacies pay

Pharmacies pay $31.94 for 30 tablets (30 × $1.06451 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 code for it: 1, calculated from the most recently completed pharmacy survey.

What NADAC measures · Why 30 tablets · NADAC explanation codes

All 6 NDCs

00093-9222-01 · Teva Pharmaceuticals USA, Inc. · $1.06451 per EA · eff. 2026-09-23 filed
00093-9222-05 · Teva Pharmaceuticals USA, Inc. · $1.06451 per EA · eff. 2026-09-23 filed
00093-9222-06 · Teva Pharmaceuticals USA, Inc. · $1.06451 per EA · eff. 2026-09-23 filed
14539-0673-01 · Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. · $1.06451 per EA · eff. 2026-09-23 filed
14539-0673-06 · Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. · $1.06451 per EA · eff. 2026-09-23 filed
62135-0456-60 · Chartwell RX, LLC · $1.06451 per EA · eff. 2026-09-23 filed

Compared with its class

The middle of its 6 NDCs’ NADAC prices is $1.06451 per EA filed.

Of the 154 other products in FDA’s Nonsteroidal Anti-inflammatory Drug class priced per EA, 27 have a higher middle NADAC price and 127 a lower one. The one in the middle is INDOMETHACIN 25 MG CAPSULE, at $0.09341 per EA filed (eff. 2026-09-23).

Prices are compared per unit, whatever the strength or dose, and a class is not a list of substitutes.

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

How the class comparison works

What Medicare paid

Medicare Part D paid $26.16 for 30 tablets, at an average of $0.87187 per EA in 2024 (2024-01-01 to 2024-12-31) for “Diflunisal”, every strength and form sold under that name together (Medicare Part D Spending by Drug, file of 2026-06-25).

That average covers 9,163 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 30 tablets? 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 DIFLUNISAL 500 MG TABLET 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 Diflunisal / Diflunisal: 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 generic name.

Its pharmacologic class

Nonsteroidal Anti-inflammatory Drug 189 products