How to Read Japan's NHI Drug Price List (薬価基準): A Guide for Market Access Teams

For global pharma market access and pricing teams, Japan's National Health Insurance (NHI) Drug Price Standard — known in Japanese as the yakka kijun (薬価基準) — is one of the most consequential documents in the entire reimbursement landscape, and also one of the hardest to use. It is published only in Japanese, distributed as dense spreadsheets covering more than 17,000 line items, and updated on a schedule that mixes routine quarterly listings with sweeping biennial revisions. For a team based outside Japan trying to benchmark a molecule, track a competitor's price trajectory, or forecast the impact of an upcoming revision, simply locating the right row in the right file can be a real obstacle. This guide walks through what the list is, how each entry is structured, and how prices move through it over time.

What the NHI Drug Price List Actually Is

The yakka kijun is not just a price catalog — it is the legal instrument that determines which drugs are reimbursable under Japan's universal health insurance system. A drug that is not listed cannot be prescribed and reimbursed through NHI channels, regardless of whether it holds regulatory approval from the PMDA. This is a critical distinction for foreign manufacturers: approval and reimbursement are two separate gates, and the price list is the record of the second one.

The Ministry of Health, Labour and Welfare (MHLW) maintains the list and updates it through new listings roughly four times a year, as newly approved drugs and generics clear the pricing process administered by the Chuikyo (中央社会保険医療協議会, Central Social Insurance Medical Council). Separately, the list undergoes a comprehensive price revision on a roughly biennial cycle, most recently applied in FY2025, alongside interim adjustments in off-years that have become more common in recent revision rounds. Each revision can touch thousands of existing listings at once, which is why static exports of the list age quickly.

Anatomy of a Single Listing

Each row in the yakka kijun generally represents one product at one specific dosage form and strength — not one active ingredient. This is a frequent point of confusion: a single molecule can appear across dozens of rows once originator, biosimilar, and multiple generic manufacturers are all listed at their own specifications. Typical fields include:

• Drug price code (薬価コード) — a numeric classification code that groups the product by therapeutic category and formulation, used for pricing administration.
• YJ code — a standardized identifier used across the Japanese healthcare system for drug management and increasingly linked to GS1 distribution codes as MHLW's data infrastructure modernizes.
• Product (brand) name and manufacturer — listed exactly as approved, which can differ from the name used in other markets.
• Dosage form and strength — tablets, injections, and other formulations are listed separately even for the same ingredient.
• NHI price (薬価) — the reimbursement price per unit, which is typically the figure market access teams are most interested in, but which only makes sense in context of the unit and packaging it refers to.

Reading a listing in isolation tells you the current price; reading it against prior revisions tells you the trend — and that comparison is where most of the analytical value sits.

How New Prices Get Set

New drug prices are not set arbitrarily. MHLW guidance generally applies one of two methods. Where a comparable drug already exists on the market, the comparable drug method (類似薬効比較方式) anchors the new price to that reference product, with premiums or discounts applied based on factors such as innovation, usefulness, and market size. Where no adequate comparator exists, the cost accounting method (原価計算方式) is used instead, building the price from manufacturing cost, R&D investment, and a regulated profit margin. Innovative therapies may also qualify for premium designations — a track global teams preparing a Japan launch plan should scope early, since the pathway chosen has a direct bearing on achievable pricing.

Revisions, Erosion, and Delistings

Once listed, a price is rarely static. Biennial revisions apply market-based price adjustments calculated from actual transaction prices surveyed across wholesalers and providers, and recent cycles have also raised the minimum statutory price floor for long-listed products by a uniform percentage. Products can also be removed from the list entirely — MHLW periodically reports batches of delistings, often numbering in the hundreds of products per cycle, typically for drugs with discontinued manufacturing or negligible remaining sales. For a market access team tracking a mature portfolio, delisting risk is often as important to monitor as the price level itself.

Keeping Track Without Reading Japanese Spreadsheets Every Quarter

Because the yakka kijun changes incrementally throughout the year and comprehensively every revision cycle, manually tracking even a modest portfolio against it is a recurring burden for teams without in-house Japanese-language pricing analysts. NHI Price Wire tracks all 17,000+ NHI-listed drug prices in English, updated as MHLW revisions take effect, so global pharma teams can monitor listings, price changes, and delistings without parsing the source files themselves. If Japan pricing intelligence is part of your market access workflow, it's worth trying the dashboard directly.