Consumer Price Index
Bureau of Labor Statistics > Consumer Price Index > Methods > Seasonal Adjustment

The Consumer Price Index (CPI) produces both unadjusted and seasonally adjusted data. Seasonally adjusted data are computed using seasonal factors derived by the X-13ARIMA-SEATS Seasonal Adjustment Method. These factors are updated with the release of January data in February and reflect price movements from the previous calendar year. The new factors are used to revise the previous 5 years of seasonally adjusted data; older seasonally adjusted indexes older are considered to be final.

Attention
  • Recalculated seasonally adjusted indexes and seasonal adjustment factors for January 2015 through December 2019 were made available on Tuesday, February 11, 2020. The revised indexes and seasonal factors are available on this page, as are the technical files (Specification files) used in the production of seasonally adjusted indexes for this year.

Data

  • Revised seasonally adjusted indexes and factors, 2015-2019 (XLSX)
  • Seasonal factors table, 2020 (PDF)
  • Series changing seasonal status, 2015-2019 (PDF)
  • Components of seasonally adjusted all items, 2020 (PDF)
  • Intervention analysis in seasonal adjustment, 2020 (PDF)
  • Specification files, 2015-2019 (ZIP)
  • Used cars and trucks data, 2019 (XLSX)
  • Archived seasonal adjustment data

 

Last Modified Date: February 11, 2020