PCLASS_VERSION indicates the version (yyyy.n) of the Procedure Classes for ICD-10-PCS tool where yyyy indicates the fiscal year for ICD-10-PCS procedure codes and n indicates the release number within the fiscal year. The Procedure Classes is valid for ICD-10-PCS procedure codes from October 1, 2015 (the start of ICD-10-PCS) through September of the designated fiscal year. For more information, please refer to the Procedure Classes for ICD-10-PCS page, including a log of changes between versions, of the HCUP User Support website under Tools and Software.