Japan Kept Its Plan to Widen Cost-Effectiveness Adjustments After a 2026 Review

Japan applies cost-effectiveness evaluation after listing to selected medicines, medical devices and regenerative medicine products. Manufacturers prepare an analysis following the official guideline, and C2H conducts the public analysis, which reviews and, where needed, reanalyses the manufacturer’s submission. C2H states that the process takes about 15 to 18 months. The results are used by Chuikyo to adjust the price of the product.

The current English version of the guideline states that it was approved by Chuikyo on 17 January 2024 and that the Japanese version takes precedence where the two differ. Earlier versions were approved in 2016, 2019 and 2022. C2H’s guideline page also lists related notifications dated February 2026; whether a newer guideline edition has been issued should be checked on the C2H site.

The guideline sets out the methods that manufacturers must use, including the choice of comparator, the analytical perspective and the approach to outcomes and costs. Because C2H reviews the submission and may conduct its own reanalysis, differences between the manufacturer’s analysis and the public analysis can determine the final result. A published study comparing manufacturer and public analyses in Japan has examined where such differences arise, which manufacturers may find useful when anticipating likely points of disagreement.

Chuikyo began discussing the FY2026 reform in July 2025, with a focus on clearer rules for designating and re-designating products for evaluation, including after market expansion. On 26 December 2025 Chuikyo approved the FY2026 reform outline. According to trade press, the council kept the direction of expanding price adjustments based on cost-effectiveness evaluation but agreed to hold off on implementation and to run a six-month period of technical discussions, including third-party verification of existing results. Associated handling rules were approved in January 2026.

Before the reform, industry associations had called for changes to the system. A December 2025 joint statement by Japanese and foreign industry bodies addressed the FY2026 drug pricing and cost-effectiveness reforms. Commentators report that discussions included extending adjustments beyond the premium portion of a price to the base price; this reading comes from secondary commentary and should be checked against Chuikyo materials.

Trade press reported that the technical discussions were planned to revisit around 40 assessed products in public sessions, with a report to the Chuikyo cost-effectiveness subcommittee in September 2026. Headlines published on 19 August 2026 and 8 September 2026 state that the review group wrapped up its technical debate, urged more access for companies to the process, found past decisions sound and saw room for more transparency.

On 30 September 2026, according to trade press, a Chuikyo panel backed plans to expand cost-effectiveness-based price cuts by the end of 2026 and did not accept the industry’s request for a freeze on adjustments. The final text of the revised rules had not been confirmed from primary sources at the time of checking.

The technical review was intended to address concerns from industry about the consistency and transparency of past evaluations. The reported conclusion that past decisions were sound, combined with the call for greater company access, suggests that the main elements of the system will continue while procedural changes may be made to how companies take part. The details of any such changes should be confirmed in Chuikyo and C2H documents as they are published.

Experience to date shows that evaluations often lead to price reductions. Secondary commentary reports that 38 of 49 evaluated items were judged to have low cost-effectiveness, and Eisai reported in July 2025 that Chuikyo’s evaluation of lecanemab (Leqembi) led to a price reduction of 15 per cent. Manufacturers should expect wider adjustments to raise the commercial stakes of the analysis.

Companies with products that may be selected should prepare analyses that follow the guideline closely, anticipate C2H reanalysis of key assumptions, and plan for greater transparency in the process. This summary by Pubrica is informational and does not represent the views of Chuikyo, the Ministry or C2H.

The interaction between cost-effectiveness evaluation and other pricing rules also matters, since adjustments apply to listed prices that have already been set under the NHI drug pricing system. Companies should coordinate their cost-effectiveness strategy with their wider pricing and launch planning in Japan, and keep the timing of evaluations in view when planning indication expansions that could trigger re-designation.