In April 2019, Japan formally introduced health technology assessment (HTA) and, more specifically, a cost-effectiveness analysis, to inform healthcare decision making, mainly when it comes to the pricing of new technologies. This article provides an overview of this new policy, which was implemented formally after a pilot program. In the fiscal year (FY) 2012, discussions on cost-effectiveness assessments were initiated in Japan. After 7 years of deliberations, a cost-effectiveness assessment was implemented formally in April 2019. In Japan, the cost-effectiveness analysis has been used to inform price adjustments of healthcare technologies, although it has not yet been used for decision making on insurance coverage. Selection criteria were established because not all drugs and medical devices could be evaluated owing to a shortage of experts. Exclusion criteria have also been applied to prevent access restriction. The scope of the evaluation’s price adjustment target is limited to part of the product price. If the cost per quality-adjusted life-year (QALY) threshold falls below ¥5 million per QALY, the price adjustment rate changes stepwise according to the cost per QALY. In addition to price reduction, a price-raising scheme has also been implemented for scenarios where products are evaluated to be highly cost-effective and innovative. This article describes the first formally implemented HTA system in Japan. Although it is too early to make any conclusions about its effect, the Japan-specific context makes this system unique. To fully understand the opportunities and challenges of the new system, it is vital that Japan accumulates experience with this system and develops human resources in health economic evaluation.