US prices are gross of confidential manufacturer rebates, so they overstate net US prices by an unknown share.
US vs Canada, molecule by molecule
The same active molecule sells at two prices on two sides of the border. This ledger starts from 500 high-spending Medicare Part D molecules and matches each against Canadian price references, one molecule per row, so the gap is a number instead of an anecdote. 194 match. The rest are listed with US data only.
194
molecules matched
66.7x
largest US-to-Canada price ratio (Rivaroxaban)
US$125.5B
Medicare Part D spent in 2024 on matched molecules
4.4x
median US-to-Canada ratio across matched molecules
Explorer
Type a molecule name, a brand, or an ATC code. Each row shows US per-unit cost from Medicare Part D 2024 beside the Canadian reference price, with the ratio between them.
| Molecule | ATC | US per unit | Canada per unit | US / Canada |
|---|---|---|---|---|
| RivaroxabanXarelto | B01AF01 | US$17.30US figure is gross of rebates | US$0.26 | 66.7x |
| Latanoprostene BunodVyzulta | S01EE06 | US$98.84US figure is gross of rebates | US$1.53per mL | 64.5x |
| Dapagliflozin PropanediolDapagliflozin, Farxiga | n/a | US$18.23US figure is gross of rebates | US$0.38 | 47.8x |
| BimatoprostBimatoprost*, Durysta | S01EE03 | US$92.81US figure is gross of rebates | US$2.24per mL | 41.5x |
| CanagliflozinInvokana | A10BK02 | US$18.58US figure is gross of rebates | US$0.53 | 35.2x |
| ApixabanEliquis | B01AF02 | US$9.63US figure is gross of rebates | US$0.30 | 32.3x |
| Sitagliptin PhosphateJanuvia | n/a | US$17.96US figure is gross of rebates | US$0.60 | 30.0x |
| TravoprostTravatan Z, Travoprost | S01EE04 | US$33.36US figure is gross of rebates | US$1.15per mL | 29.0x |
| PegfilgrastimNeulasta, Neulasta Onpro | L03AA13 | US$10,307.04US figure is gross of rebates | US$359.18per container | 28.7x |
| MirabegronMirabegron ER, Myrbetriq | G04BD12 | US$14.56US figure is gross of rebates | US$0.53 | 27.3x |
| EnzalutamideXtandi | L02BB04 | US$136.49US figure is gross of rebates | US$5.33 | 25.6x |
| TicagrelorBrilinta | B01AC24 | US$7.26US figure is gross of rebates | US$0.29 | 25.1x |
| ClobazamClobazam, Onfi | N05BA09 | US$3.98US figure is gross of rebates | US$0.16 | 24.8x |
| Lisdexamfetamine DimesylateLisdexamfetamine Dimesylate, Vyvanse | n/a | US$10.02US figure is gross of rebates | US$0.42 | 24.1x |
| Bromfenac SodiumBromfenac Sodium, Bromsite | n/a | US$86.71US figure is gross of rebates | US$4.00per mL | 21.6x |
| EtanerceptEnbrel, Enbrel Mini | L04AB01 | US$1,819.32US figure is gross of rebates | US$87.97per container | 20.7x |
| AdalimumabHumira, Humira Pen | L04AB04 | US$3,505.99US figure is gross of rebates | US$172.02per container | 20.4x |
| EstradiolClimara, Divigel | G03CA03 | US$1.70US figure is gross of rebates | US$0.09 | 19.5x |
| BrexpiprazoleRexulti | N05AX16 | US$49.56US figure is gross of rebates | US$2.56 | 19.4x |
| Adalimumab-AdbmAdalimumab-Adbm(Cf), Adalimumab-Adbm(Cf) Pen | n/a | US$3,216.58US figure is gross of rebates | US$172.02per container | 18.7x |
| MetronidazoleFlagyl, Metrogel | A01AB17 | US$0.78US figure is gross of rebates | US$0.04 | 18.6x |
| DasatinibDasatinib, Sprycel | L01EA02 | US$411.53US figure is gross of rebates | US$24.01 | 17.1x |
| BosutinibBosulif | L01EA04 | US$265.63US figure is gross of rebates | US$15.65 | 17.0x |
| Varenicline TartrateChantix, Tyrvaya | n/a | US$5.22US figure is gross of rebates | US$0.34 | 15.5x |
| UstekinumabStelara* | L04AC05 | US$13,766.05US figure is gross of rebates | US$911.08per container | 15.1x |
per dosage unit: us figure is gross of rebates.
Findings
Each finding below is computed from the ledger. The US column is Medicare Part D 2024, gross of confidential rebates, which overstates net US prices by an unknown share.
Which molecule has the widest US-to-Canada price gap?
Rivaroxaban costs 66.7x more per unit in the US than in Canada
One Rivaroxaban dosage unit costs $17.30 under Medicare Part D against $0.26 through Ontario's public drug plan. The five widest gaps are Rivaroxaban (66.7x), Latanoprostene Bunod (64.5x), Dapagliflozin Propanediol (47.8x), Bimatoprost (41.5x), Canagliflozin (35.2x). US figures are gross of confidential rebates, so treat each ratio as an upper bound.
What is the typical gap, not just the extreme?
The median molecule costs 4.4x more in the US
Across 194 matched molecules, the median US-to-Canada per-unit ratio is 4.4x. 54 molecules sit under 2x, while 61 sit at 8x or more. The gap is structural, not a handful of outliers.
How much spending does the ledger cover?
$125.5B in 2024 Medicare Part D spending across 194 molecules
The matched molecules account for $125.5 billion of 2024 Medicare Part D spending, so the gaps describe where most of the money goes, not a niche corner of the market.
Which drug classes have the widest gaps?
Sensory organs leads at a 41.5x median ratio
By ATC level-1 class, Sensory organs (S) has the widest median gap at 41.5x across 4 molecules. Some classes are structurally cheaper in Canada than others, which is where negotiation leverage concentrates.
What happened to the Rinvoq anecdote?
Upadacitinib (Rinvoq): 5.8x
The often-quoted Rinvoq comparison is one row of 194 here: $217.14 per unit in the US against $37.73 in Canada. The ledger replaces the anecdote with a number anyone can check.
Charts
Real values from the ledger, hand-drawn as SVG. Hover for exact numbers.
Per-unit price ratios for the molecules with the widest gaps. US numbers are gross of rebates.
How many molecules fall into each ratio band. Most molecules sit in a narrow band, while a long tail pays far more in the US.
Median US-to-Canada ratio per ATC level-1 class. Some classes are structurally cheaper in Canada than others.
Methodology
Every rule below is the code in scripts/, not a description of intent. The pipeline is re-runnable.
01
The CMS file repeats every drug once per manufacturer plus an Overall rollup row. Only Overall rows are used, so no dollar is counted twice. 3,625 unique drugs remain for 2024.
02
Generic names are lowercased, spacing collapsed, and strength suffixes stripped, so brand Eliquis and generic apixaban become one molecule row. Dosage forms stay out of the key. A molecule is a molecule.
03
Each normalized molecule is searched against the RxNorm REST API for an ingredient-level RxCUI, and the ATC code is read from its properties. Matches below the confidence bar are quarantined, never guessed.
04
Total 2024 Part D spending divided by total 2024 dosage units per molecule, spending-weighted. This is gross of confidential manufacturer rebates, which CMS is prohibited from disclosing per drug, so it overstates the net US price by an unknown share.
05
PMPRB publishes no machine-readable molecule-level price file, so the Canadian column uses the Ontario Drug Benefit e-formulary: the lowest Drug Benefit Price per unit across matched formulary rows, converted at the 2024 Bank of Canada average USD/CAD rate. That is the price Ontario's public plan pays pharmacies, not a national list price. Molecules with no formulary listing are shown with US data only and labeled honestly.
06
On September 30, 2026 CMS finalized the GLOBE model, which ties Part B rebates to benchmarks from 19 countries including Canada. The gaps in this ledger are the reason that policy exists. The ledger does not attempt to model what GLOBE would do to them.
Developers
REST with OpenAPI 3.1, a JSON-RPC MCP server for agents, and the full ledger as CSV. No key needed.
/api/v1/summaryGET/api/v1/molecules/search?q=apixabanGET/api/v1/molecules/apixabanGET/api/v1/gaps/ranking?limit=50GET/api/v1/atcOne row per molecule: US spending, per-unit costs, Canadian reference price, ratio, ATC class, RxCUI.
Download molecule-ledger.csvFor AI agents
Three tools over streamable HTTP: look up one molecule, rank the gaps, break down by drug class.
Add this MCP server to Claude Code: {{"mcpServers": { "molecule-price-gap": { "url": "https://this-site.example/mcp" } }}}. Then look up the US vs Canada price gap for upadacitinib..Data
Two government sources, one standard crosswalk, one currency series. Nothing else enters the ledger.
Centers for Medicare & Medicaid Services (US)
Annual per-drug spending file: 3,625 unique drugs in the 2024 release, five years of history per row, manufacturer-level detail behind Overall rollups. Gross of confidential rebates.
Ontario Ministry of Health
DIN-level Drug Benefit Prices. The ledger takes the lowest price per unit across matched formulary rows for each molecule, the price Ontario's public plan pays pharmacies. Retrieved October 10, 2026. PMPRB publishes no machine-readable molecule-level price file, which is why the formulary is the Canadian source.
US National Library of Medicine
Ingredient-level RxCUI search plus ATC property lookup, one query per molecule, results cached in data/rxnorm_cache.json.
Bank of Canada
Daily exchange rate series averaged over 2024, used to express Canadian prices in USD for the ratio.