Main and
  The PSID's Main and Supplemental Studies are available in zipped format (with the exception of CDS-I and CDS-II variables; to be integrated soon). In order to merge these files, please see the following information on the Merging PSID Data Files as well as the FAQs on 'How to Use the Data'. Please note all of the contained variables can also be accessed through the Data Center.
Early Release   The Early Release files contain preliminary data and documentation of Main and Supplemental Studies before they are released in their final edited form. Upon final release, this information is distributed through the Data Center and in packaged form through the Main and Supplemental Studies page (see above).
Auxiliary Files   Auxiliary Files contain variables from special data collection or data generation projects. These files are available for only selected years and their structure does not allow integration into the Data Center. Users may want to review the set of auxiliary files to identify additional variables of interest.