On November 20, 2025, version 1.20.2 of the JWST Calibration Pipeline will be made operational as a part of Build 12.1. This build will be used to process all new data obtained by the observatory and to reprocess all existing archival data, which takes about 4 to 5 weeks. Users can also reprocess their own data immediately using Build 12.1 and associated reference files. New calibration reference files will be used automatically with the updated software.  Please use the MAST subscription service to receive notifications when the data has been reprocessed.  

Build 12.1 provides improvements for multiple observing modes and fixes several outstanding known issues.  A full list of improvements for this build can be found in JDox on the Operations Pipeline Build pages, along with a list of current known issues and future improvements.  Highlights for Build 12.1 include:

• Updates to the MIRI time-dependent count rate model, photometric calibration, absolute astrometric calibration, and improved performance for some bright sources.
• Automatic source-centroiding for MIRI and NIRCam imaging time-series observations, improving photometric accuracy for some observations.
• Updated NIRSpec IFU and MOS flux calibrations.
• A new option to automatically determine the best configuration for optional 1/f noise correction for NIRISS and NIRCam imaging observations.

Observers are invited to contact the JWST Help Desk with further questions, for support, or to provide input on pipeline issues.