Each year with the release of the January CPI, seasonal adjustment factors are recalculated to reflect price movements from the just-completed calendar year. This routine annual recalculation may result in revisions to seasonally adjusted indexes for the previous 5 years. Recalculated seasonally adjusted indexes as well as recalculated seasonal adjustment factors for the period January 2016 through December 2020 were made available on Monday, February 8, 2021. The revised indexes and seasonal factors are available at Seasonal Adjustment in the CPI. For seasonally adjusted series specifically impacted by the COVID-19 pandemic, additional information was made available at the same time.