The Bank of Japan’s Research and Statistics Department has started publishing a monthly estimate of consumer price inflation that excludes “institutional factors” in order to better capture underlying price developments. The series is available on the Bank’s Indicators for Core CPI webpage alongside indices previously released as Measures of Underlying Inflation. The new “CPI that excludes institutional factors” removes staff-estimated effects from the official CPI published by Japan’s Ministry of Internal Affairs and Communications, including changes in the consumption tax rate, policies on free education, the 2021 reduction in mobile phone charges, travel subsidy programmes, and measures to reduce energy cost burdens such as gasoline prices and electricity and gas charges. Three CPI definitions are published (all items less fresh food, all items less fresh food and energy, and all items less food and energy), and the Bank notes the definition of institutional factors may change without prior notice; the trimmed mean, weighted median, mode and diffusion index series remain the same as previously published indicators. Data are, in principle, released at 2:00 p.m., two business days after the official CPI release.